I guess you could run some sort of a proxy or a blog network. Those networks do really well, especially if you put them on different hosts and link them to each other. I'm sure that you'll be able to earn at least the renewal fees.
There are some more techniques though...like putting a contest for posting in your site...or something else to give them access to the domain name....in a way u won't transfer the domain to them....u'll have all rights on domain but they can use the name untill u want it....also for posting in a forum or something else...some contest u'll get money over that place.. just an idea