I am still in need for a copy of L4D2. I also have a gift of HL2 and HL2: Ep 1 to trade.
Dell has L4D2 for $30 right now, but you won't get till mid December.
Not gonna hype it. Just look if you are interested.
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=006&sspagename=STRK%3AMESE%3AIT&viewitem=&item=160058905610&rd=1&rd=1