Actually, what I will always take is the better card-- that's what I look at, not the sticker applied by some random kid.
I think most sellers would consider me a "real buyer." And yes, I will pay you an "8" price for a dead centered 7 that looks better than many 8s. What's more, as shocking as this may sound, I won't pay a penny for an ugly 8 no matter what the sticker says. It's not that I will pay you "an 8 price for a 7," if we mean any 8 or any 7. Because not all cards with the same sticker grade are identical, nor do they all sell for the exact same prices each and every time. Despite sticker grades, each and every card is unique.
If you do go in search of the gorgeous high-end 7 that will command 8 money, like Peter's card, for example, you will find it is a much rarer thing than the average 8.
So are you collecting these cards, or is it just that you can't wait to sell your 8s so you can get more money for them than you would 7s? If I read your post correctly, you are saying that for the same exact money, you will take the admittedly uglier card in the higher grade holder because of possible resale, as opposed to actual enjoyment during ownership. Which makes it all about the $.
On the money topic, the fact is there are indeed 7s that are better looking cards and will command more money at auction than some of your 8s. Since you seem to study past ebay sales, you will surely note that for every average card in a certain grade, there are outliers that are lower graded that sell for at or even over the average of the next grade up. Those cards-- like Peter's stunning Williams card-- will actually sell faster and better than an ugly or so-so card with a sticker that shows the next grade up. I'd actually wager that a hypothetical grouping of HOFer cards, all high-end 7s, painstakingly curated by a collector, each card with perfect centering, will actually sell faster and for more than an all 8 grouping with average to poor eye appeal for the grade.
If the SOLE focus is stickers (sole being the key word here; I have nothing against slabbed cards, and collect them as well as raw) there are definitely good places for such sticker collections...
