Bonanzle is basically a fixed price marketplace with the option to make offers. I don't specifically know of anyone selling coupons there, but it is a fun and vibrant place to sell your goods. They are not looking to have sellers with mass merchandise-type booths, but really focusing on smaller sellers with unique items. Come on over and check us out! It is free to list and final fees are very low...
Christy
http://www.bonanzle.com/kayceestudios