Take a look at DomainApex.com It is an aftermarket domain sales/auction site ran by DirectNic, a reputable, established registrar. I believe it has excellent potential. You will see some obvious bogus bids but this is practically unavoidable with a site of this nature. The site is fairly new but very functional and has produced several offers for me already. Personally, I purchase domains for development but for those that I'm willing to sell, I feel this is as good of a venue as any. On one occasion I emailed support about a minor issue and they responded within an hour so needless to say I was very impressed. There is no fee to list.