At Best Buy you can buy the PC version of COD 4 for 39.99 with free shipping (I'm pretty sure they will add tax.)
http://www.bestbuy.com/site/olspage.jsp?skuId=8428597&st=call+of+duty&type=product&id=1181832841903&AID=10474050&PID=404255&URL=http%3A%2F%2Fwww.bestbuy.com%2Fsite%2Folspage.jsp%3FskuId%3D8428597%26st%3Dcall%2Bof%2Bduty%26type%3Dproduct%26id%3D1181832841903
http://www.bestbuy.com/site/olspage.jsp?skuId=8428597&st=call+of+duty&type=product&id=1181832841903&AID=10474050&PID=404255&URL=http%3A%2F%2Fwww.bestbuy.com%2Fsite%2Folspage.jsp%3FskuId%3D8428597%26st%3Dcall%2Bof%2Bduty%26type%3Dproduct%26id%3D1181832841903
