Serious Sam 3 BFE is on sale thru a UK gaming site for $9.99 retail is 39.99 and right now Steam has it on sale for $19.99
I bought it thru the UK game site (link below) no issues. And they emailed me the key with in seconds of the purchase. Game downing from steam now.
Great LAN multiplayer game!
http://www.getgamesgo.com/product/serious-sam-3-bfe