Recently joined up the new site miniaturebids.com, a global auction site meant for miniatures, models, game stuff, etc.
Free to join, no listing fee and no fees at the end of a listing, plus you can put something on there for pretty much as long as you want. There are categories for GW, Fantasy Flight and other companies & categories, although the organization could be overseen a bit better (the Fantasy Flight section has Magic the Gathering cards in it the last time I checked, that sort of thing). The messaging system needs some work as well but it works OK right now, it’s just a bit clunky.
Payments are by Paypal only, so any disputes are handled through them, for better or for worse.
Overall it’s pretty good! For no listing or ending fees it’s definitely worth it and there’s already loads of sellers on there, including people selling really old vintage models and custom commissions.