Can't buy Hitman 3 on Steam? No buy button?

A week or two ago there was a buy button for Hitman 3 for me on Steam, and now its gone. How do I acquire this game??

For reference I have Hitman 1 and Hitman 2 on Steam already.

From searches it seems like sometimes this happens if the game is part of a bundle, but I can't find any bundle that lets me buy either.