You can get Bioshock 1 + 2 for $44.99, or, if you buy with 3 more friends, it goes down to $34. And everyone gets Bioshock too.
The problem is that Bioshock 2 uses GFWL (that probably means that there won't be dedicated servers) and I know some are bothered by SecuROM too.
And if you already have a copy of Bioshock 1, you can gift the extra copy to a friend.
the words above were backed by NUCLEAR WEAPONS!