I was browsing ebay and saw this sealed copy of Halo 2 for a BIN price of $20 + $4 shipping.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=62053&item=8167894333&rd=1
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=62053&item=8167894333&rd=1