There's a good chance you already own BioShock: The Collection through PlayStation Plus, but if you happened to have missed out on that excellent deal, you can now purchase each entry in the franchise on its own. No longer tied to a bundle, BioShock Remastered, BioShock 2 Remastered, and BioShock Infinite: The Complete Collection have been listed on the PlayStation Store at £15.99 each.
They haven't been added to the US alternative just yet, but we have to assume they will pop up in due course. There's no need to pick these titles up if you already own the full collection, however. These are the exact same products which come with the same base game along with all the corresponding DLC. We suppose if you just really want to play a particular title without buying the entire series in one go, that is now a viable option. They'll be real bargains when they go on sale too.