Batman: Arkham Collection for $25. Contains Arkham Asylum and Arkham City (both remastered), and Arkham Knight. No Arkham Origins, as that was done by a different publisher.
Also includes all DLC, so that means all skins and vehicles, some of which they charged a couple of bucks for previously.
These are some of my favourite games, even better than Spider-Man IMO. Arkham Knight is probably the weakest of the three, but I still enjoyed it greatly.
Cheapest I've seen for a physical copy is around $50.
Time to start seriously concussing the bad guys, but don't kill them because Batman doesn't kill…crippling is ok, but no killing…