The tech forum Hardware Secrets regularly sells off the stuff that they acquired for various reviews.
They're having a mega sale that ends in just over 3days (7/13 ~3pm Pacific time). There's almost 30 video cards and 6 motherboards. Sometimes the stuff goes for under $20, so can occasionally get really good prices if you're not picky.
No reserves, free shipping, and minimums are always $1, as they're just trying to clear out stuff they don't need.