I will thanks. I admit I used the AH at the start of nightmare on my DH, since this was my first character and I was really struggling for a decent bow. Haven't used it since then on that character, simply because I chose not to after that, the bow essentially made NM trivial. (I did use the AH to get some +exp gear for my wizard, and that made levelling much more trivial.)
I parked my DH for a while at act2 hell I think, whilst I leveled a wizard. Or tried to while the servers died. I picked up my DH again (after the nerfs) and am currently near the end of act2 Inferno, all done solo, only 1 item purchased from the AH in an earlier difficulty, and it's all going pretty well thanks.
I'm sure it would be easier if I bought something, but I don't particularly want easier, I'd just play NM for that. I guess I'm just of the mindset that as long as what I have is *good enough* I don't need to cry and moan that other people had it easier, or classes need a nerf, or the grass is greener over there. Of course if the difficulty makes people lose desire to play then you should use the AH to prolongue your experience. For me this is the other way around.
In a loot based game, I desire loot. But I want my loot, not someone elses. Each to their own of course, but Inferno is not impossible, and I will finish it solo