There will be math... 0

[valiantman]

Playing with simple calculations for the different prices of CGC graded books (universal)... there'll never be a formula that takes into account every possible difference between comics, so let's just agree that we're going for simplicity here.

If you have...

P = a known price (recent sale, whatever)

G = the grade (universal) for that P

... and you want to calculate

V = value of some target grade

T = the target grade you want to know V

 

Then a simple calculation for value would be:

V = (P x T) / (G)

 

Example:  P = $500, G = 9.0, T = 8.0, find V (the value of the 8.0):

V = ($500 x 8.0) / (9.0) = $444

 

With me so far?  No?  Ok, see you later. 

 

...but what about the CGC Census?  Shouldn't it matter how many 8.0 or 9.0 or 9.8 copies there are?

Yep.

C = Census count for grade G or better (include G and all universal grades higher than G)

O = Census count for the Other grade T (include T and all universal grades higher than T)

 

Now, a simple calculation for value which includes the CGC census would be:

V = (P x C x T) / (G x O)

 

Example:  P = $500, G = 9.0, T = 8.0, C = 40, O = 80, find V (the value of the 8.0 with 80 copies or better on the CGC census):

V = ($500 x 40 x 8.0) / (9.0 x 80) = $222

 

Are we having fun yet? 

[valiantman]

Keeping the same example (a 9.0 sold for $500), and trying to find the value of 9.8...

V = PT / G would be $544

But using the CGC census for 9.8 or better, let's say there are only 8 copies at 9.8 or better...

V = PCT / GO would be $2,722

[valiantman]

This formula works fairly well, except for the "single highest graded copy" scenario (or really any scenario where there's only a few highest grade and several just below it).  If there's only 1 copy at 9.8 in our example where the 9.0 sells for $500 and there are 40 copies at 9.0 or better, the single 9.8 would result in $21,778.  That's probably too high... unless you own that single highest book. 

[valiantman]

Think through the "just saying it, not mathing it"... the first formula, which doesn't care about the CGC census numbers basically says:

9.8 = $98

9.0 = $90

8.0 = $80

0.5 = $5

While the second formula says:

If the 9.8 (or better) happens five times less often than the 9.0 (or better), then the 9.8 is five times the value of the 9.0 (plus a little bonus for 9.8 being a higher grade than 9.0), and if the 8.0 (or better) is twice as many as the 9.0 (or better) then the 9.0 is twice the 8.0 value (plus a little bonus for 9.0 also being a higher grade than 8.0).

The actual market price is probably always(?) between these two calculations... so if nothing else, these two simple(?) formulas probably set the absolute min/max prices for any other grade, if there is a recent sale. 

Edited September 4, 2018 by valiantman

[blazingbob]

This price calculator needs to be a google search item - the Valueant price calculator..

Your contribution to the comic selling world

Edited September 4, 2018 by blazingbob

[valiantman]

The formula is pretty useless at the extremes (single CGC 9.9 for Hulk #181), but otherwise... 

Remember... it's only using a single sale for a single grade (a $3,500 CGC 7.5, in this example)... which is silly for a book like Hulk #181, but for many other books, a single recent sale for a single grade might be all we have. 

Edited September 4, 2018 by valiantman

[Artboy99]

I think you would need to add another variable to the formula that is intended to capture recent "trends" in specific markets. Like the previously mentioned Hulk 181.

Or for another example the CGC 8.0 Famous Funnies 213 that sold for $6000.00

( 8.0 )  $6,000 Aug-2018

( 7.5 )  $1,445 Jul-2017

In my opinion this anomaly of seeing a price on a sold book that is far more than double what it "should" have sold for when compared to the previous sale a year ago on a very similar grade of book is more than a one-off outlier. The trend here could be noted as

1. classic cover + 2. golden age + 3. high grade 4. collectible/ desirability = value modifiers

There are many more examples of this price increase within golden age collecting, and your formula calculator needs to include it.

[valiantman]

1 hour ago, valiantman said:

there'll never be a formula that takes into account every possible difference between comics, so let's just agree that we're going for simplicity here.

 

4 minutes ago, Artboy99 said:

The trend here could be noted as

1. classic cover + 2. golden age + 3. high grade 4. collectible/ desirability = value modifiers

There are many more examples of this price increase within golden age collecting, and your formula calculator needs to include it.

I see my first post wasn't strong enough, so I've bolded it.

How does a 7.5 not have all of the trend factors that you've noted, when the 8.0 of the same comic does?

Edited September 4, 2018 by valiantman

[1Cool]

I love the attempt to use math and census numbers to try to estimate cost of various grades.  I'd think the math would really fall apart in the lower grade keys because the low grade market flattens out quite a bit because people just want a copy so a 1.5 isn't half a 3.0 no matter what the census data is. 

[valiantman]

2 minutes ago, 1Cool said:

I love the attempt to use math and census numbers to try to estimate cost of various grades.  I'd think the math would really fall apart in the lower grade keys because the low grade market flattens out quite a bit because people just want a copy so a 1.5 isn't half a 3.0 no matter what the census data is. 

Actually, it has been.  There's a whole discussion around "Price Per Point" which is usually valid up to around CGC 6.0 or a little higher.  As a result, CGC 3.0 has generally been about double the price of the CGC 1.5.

Edited September 4, 2018 by valiantman

[Ditch Fahrenheit]

46 minutes ago, valiantman said:

Playing with simple calculations for the different prices of CGC graded books (universal)... there'll never be a formula that takes into account every possible difference between comics, so let's just agree that we're going for simplicity here.

If you have...

P = a known price (recent sale, whatever)

G = the grade (universal) for that P

... and you want to calculate

V = value of some target grade

T = the target grade you want to know V

 

Then a simple calculation for value would be:

V = (P x T) / (G)

 

Example:  P = $500, G = 9.0, T = 8.0, find V (the value of the 8.0):

V = ($500 x 8.0) / (9.0) = $444

 

With me so far?  No?  Ok, see you later. 

 

...but what about the CGC Census?  Shouldn't it matter how many 8.0 or 9.0 or 9.8 copies there are?

Yep.

C = Census count for grade G or better (include G and all universal grades higher than G)

O = Census count for the Other grade T (include T and all universal grades higher than T)

 

Now, a simple calculation for value which includes the CGC census would be:

V = (P x C x T) / (G x O)

 

Example:  P = $500, G = 9.0, T = 8.0, C = 40, O = 80, find V (the value of the 8.0 with 80 copies or better on the CGC census):

V = ($500 x 40 x 8.0) / (9.0 x 80) = $222

 

Are we having fun yet? 

Yes. 

This is known as Ratio Analysis, and has many applications.

It might be easier to see it as:

V = P(T/G)(C/O)

In other words, Value equals the product of the Price, the Grade Ratio, and the Census Ratio.

V = Price(Grade Ratio)(Census Ratio)

Using your example:

V = $500(8/9)(40/80) = $222.22

 

And yes, as you mentioned, it has its limitations.

[blazingbob]

The rocket scientist trading from Wall Street has come to the comic market.  When will the first black box of comic buyers emerge?

 

 

[Artboy99]

1 minute ago, valiantman said:

 

I see my first post wasn't strong enough, so I've bolded it.

I saw your post, my point is how valuable is the calculation tool if it isn't going to be able to do a decent value approximation in all instances.

I can figure out the value of most books easily myself if there is data, where collectors need help is in the books that have little data.

Example: what is the value of a Dark Mysteries 19 in 6.0? The last known CGC sale on GPA is from 2014 for $657 Feb-2014. I know it is worth far more than that, but how much?

The book has the following modifiers:

-in demand

-classic cover

-golden age

-copy availability :low

I love your idea, and I think there is potential for it, but could the tool be designed to approximate based on other information as I am noting above?

[thunsicker]

 

[valiantman]

4 minutes ago, Ditch Fahrenheit said:

Yes. 

This is known as Ratio Analysis, and has many applications.

It might be easier to see it as:

V = P(T/G)(C/O)

In other words, Value equals the product of the Price, the Grade Ratio, and the Census Ratio.

V = Price(Grade Ratio)(Census Ratio)

Using your example:

V = $500(8/9)(40/80) = $222.22

 

And yes, as you mentioned, it has its limitations.

Nice!  I usually find out after I come up with something from scratch that it already has a name. 

In grad school, I created a formula for data set sampling that I later found out was already called the Lincoln index.

One of these days, someone will say... "Hey!  That's new!" ... but not today. 

[valiantman]

5 minutes ago, Artboy99 said:

I saw your post, my point is how valuable is the calculation tool if it isn't going to be able to do a decent value approximation in all instances.

I can figure out the value of most books easily myself if there is data, where collectors need help is in the books that have little data.

Example: what is the value of a Dark Mysteries 19 in 6.0? The last known CGC sale on GPA is from 2014 for $657 Feb-2014. I know it is worth far more than that, but how much?

The book has the following modifiers:

-in demand

-classic cover

-golden age

-copy availability :low

I love your idea, and I think there is potential for it, but could the tool be designed to approximate based on other information as I am noting above?

I understand the market factors that you're suggesting, but I see two problems:

1) How would we quantify those additional factors?  We have the CGC Census and the recent public sale for the formula as it is... where do we get those additional numbers (and would we all agree with the data source)?

2) How do things like "classic cover" not already apply to the previous prices paid for the same book?

Edited September 4, 2018 by valiantman

[kav]

This formula needs a logarithmic function to account for the extremes.

[Scrooge]

When I cared about these things, my model would predict that the $500 in 9.0 would sell for $275 in 8.0 ... but the model was done early in the life of CGC and did not account for census population so make of that what you will. The number I get is however close to your estimation whereby there are twice as many books in 8.0 than in 9.0 so I'd favor your incorporating the census ratio in the model.

FWIW, in NM/M, the model would predict a price of ~$3,180. As you state, prices in the upper ranges are tough to predict.

In G/VG (3.0), $76 and in Fr/G (1.5), $44 from the model, so the lower grade is 60% of the G/VG, slightly higher than 50% to reflect that in the low grades, any copy is desirable to that segment of buyers.

[sfcityduck]

If you want to use math, stick with buying and selling items where price is not solely driven by emotion.  

P/E is a decent guide on what a stock should be worth if you vary the P/E to reflect the type of business.  But, comics got not E.  So, a better analogy is residential real estate bought for a non-rental purpose, where all you can work off of is "comparables" and the "feel" you have for the market (hard vs. soft) and the "curb appeal" of the house.  And those won't be enough to accurately predict selling price once you get two motivated bidders bidding for the same house (or comic) or if the market flips.

In short:  It's an art, not a science.  

 

Edited September 4, 2018 by sfcityduck

[Robot Man]

I'm an artist. I flunked math...