I generally only purchase ebooks from Smashwords (epubs) or sometimes the sony story (even though they have drm... I have a balance on a few gift cards!).
As far as price, I'm a library girl from way back who never really collected many books of her own. I'd check out 15 books every few days from the library instead. So I tend to be on the cheap side when it comes to books from authors with whom I am not yet familiar. I'll go up to $2 possibly on an independent authors who is new to me. I'd more likely to want to pay more if I have read one book and really enjoyed it. And I'm more likely to try the first book if it's free or $.99.
I think I'm a bit of an anomaly, actually, an avid reader who is not an avid book purchaser. So you can ignore my contribution
