Any advice on selling my TiVo boxes??

I hate to say it, but my time with TiVo has come to an end. I think the Fios box is now far superior for a number of reasons I won't go into.

TiVo really wants me to sell my boxes and transfer my memberships. They say there's still a thriving market for the Premiere. But I posted to Amazon and Facebook with no bites. Where is this "market" TiVo mentioned? Where should I try to sell them?