Nope, if anything, pricing is down on rehabbed bikes. The problem on garage sale and thrift store pricing, the economy has been so bad, for so long, that everybody and his brother is snagging just about anything at thrift stores, hoping to turn a few bucks. You should have seen the line in front of the musical instrument case yesterday at Goodwill. Most of the instruments never made it into the case. Buyers were all scoopers. Heck, I grabbed a couple to resell myself.
All of this has led to price compression. Prices on project bikes are up, prices on finished bikes are down. Flippers are caught in the middle. Thrift stores are selling stuff so fast, they are catching on, and pushing their prices up. And people buying at thrift stores are "assuming" everything is a good deal, I routinely watch people grab craptastic bikes at high prices. They just assume they are getting a deal.
As far as Pawn shops, I have always seen really stupid high prices at Pawn shops. Whether they get those prices or not, who knows.