It's a question that's sizzling under the surface in so many threads on these boards, so it's good that you've come out and asked it straight. For me, on a strictly limited budget, it's all about the aesthetics. I have lovely looking 3.0s and some not so attractive 6.0s so if a book has the right gloss, been stored nicely but a little bit of wear I'll often take that over something with sharp corners and ink transfer, to take two random examples.
I feel the chasing down of 9.8s is a very narrow path to follow, but then some of the arguments stated above are quite compelling, so I can see the sense in certain cases. Especially if an opportunity presents right now.