how many 9.9 and 10.0 books are there from the SA vs BA vs CA/Modern?
As far as modern books go...9.9 is the new 9.8..
That's not true, through - if you look at the modern books that are coming back 9.9 and 10.0 (Locke & Key, Invincible, etc) they are pretty much consistently ones where the cover is printed on a heavier, glossier cardstock which lends itself really well to those uber-high grades. In comparison, try finding a recent issue of Uncanny X-Men or any other book printed on regular cardstock in that high of a grade ...
Virtually_Here: That's a silly argument - true acid-free boards & mylar bags are scientifically proven to halt the decay of paper. I'm not saying that that's the only way to preserve comic books - the stacks that Church used seem to work just fine as well - but claiming that bags & boards don't make a difference is ridiculous.