I just bought in Sandy and got 2% off. That's very little off despite fairly aggressive negotiating, but it was for a house that was, IMO (and my realtor's opinion), way underpriced. Luckily for me, no one else jumped in in time to start a bidding war. In general, I would hope to get more off than 2% (maybe 5%), especially for something that wasn't priced to sell immediately.
Ps. I looked in Draper, but the prices were all over the map. Maybe that's what you're seeing.
Pps. Projections for the SL valley over the next 10-20 years show quite a bit of growth. Though prices might seem a little high, especially when compared with 10 years ago, I don't think they'll drop back down by that much. Of course, this is from someone who just bought, so take it for what it's worth.