Eye appeal has been the number one factor for me and many since the beginning of collecting. Doubt anyone is arguing against that. That typically is a major component that drives price ( though if that 5.0 copy had brittle as the page quality designation I do believe it would've sold for less, so even then you cannot say definitively that the price was entirely based on Eye appeal, but i believe that absolutely was the driving force in that copy's realized price ...as most would agree).
The ONLY point I make (that seems to be lost or ignored) is that "if" you had two books with similar/comparable Eye appeal and structure (so we've eliminated all those differentials from the equation), side by side for sale/auction, AND available at the SAME time, in the SAME venue/sales environment, THEN the differential would be the page quality , AND I "posit" that the majority of folks would be (actually already are and do) willing to pay a premium (however slight) for the better preserved copy (typically designated by pq on a cgc label) BUT...
...The books do not even have to be Graded by cgc...they can be raw and subject to the buyers physical inspection ( to even the average collector it's fairly easy to differentiate varying page quality by sight and feel , especially when you have two samples side-by-side ... and it's relatively easy to show the novice collector the differences with an actual inspection )
That is why I say GPA data is not really relevant to my discussion relating to gold/silver sales, because so few of these examples actually exist outside of the more modern era comics ( Bronze Age or newer...then the data generally does support pq differential because many 9.6/9,8 do have the same/similar eye appeal)
How anyone can believe otherwise defies my experience, but if you still don't acknowledge, well...what can I say