Buying a processor

I was wondering if anyone knows of a good website that sells used or old stock computer parts. My friend is looking to buy an AMD 1.2 Ghz athlon t-bird or duron processor for a motherboard he was given that will only hold that high of chip. My friend is hesitant about buying it off of eBay. Let me know if you have any ideas about how I can get him one cheap. Thanks.