I've been selling off large portions of my RPG library on eBay. Some great deals have been made, collectors and RPG fans have made off with some incredible bargains. I'll also be sprinkling in some old school stuff (currently the blue box!) as well.
I put up Gary Gygax's Magnum Opus: Dangerous Journeys! The most complete collection of this impressive RPG you are likely to find. Including the short run magazine that supported it.