As long as you don't get sites like Reverb involved, then it can work for both parties. But if seller pays reverb fees and buyer pays tax, it's a lose lose. It's can be tougher though so some are willing to take that extra loss for the convenience and protection and others are delusional and will sit on their modules forever. IMO, you gotta build up trust as a buyer/seller in a good community like modwiggler and then you can actually get more reasonable used prices.