I want to know that too. I've seen an Offers over $480 sell for $450, and another offers over $495 sell for $535. Yes the $535 was actually substantially better, but I thought it was actually closer to 15k better, not $85k better.
I'm going along with what people have said here. Figure out what I think it's worth, offer about 5% below that, and come up to just short of what I believe it's worth. If a place I saw a few weeks ago is still for sale, I think I will put in an offer soon.
BTW, I am now back in the market after getting engaged, and being convinced that what is left of the "crash" (all 8-16% of it in my desired suburbs), is not worth the disappointment of not having a marital home to move into.
