Two prices:
1. Sell to stranger. You find this price by looking for you PC on ebay, and remembering the ones you see have not sold yet so the selling price is lower, and that your seller history (or lack of) will affect the price.
2. Sell to a friend with implied/explicit "If it fails in a month or you decide you hate it I will give you the money back". Somewhat above the EBAY trusted seller price.