Tesco seem to be getting rid of some PC surplus over the weekend, including Medal Of Honor: Warfighter for an insanely cheap £1.75. Though I chastised this incredibly unambitious shooter in my Medal of Honor: Warfighter Review, much is forgiven at this price, but I can't personally vouch for whether it still has a functional multiplayer community.
Still, PC games tend to retain their player bases far longer than the console versions. And again, this is an incredibly cheap PC deal so long as you click and collect. Thanks to ABrune @ HUKD!