No sure about you guys, but I find it hard to sell items on ebay when I'm competing against MegaSellers. It's much more effective to sell or buy an item on Craigslist. Can't beat free postings and local sellers and buyers! Craigslist FTW! =)

Amazon Marketplace is great as well. I remember taking 4 boxes of books to a used book store a few years back and being offered $17. I instead sell them on Amazon Marketplace used and get over $200.