Well you can get xbox controllers that are made like ps3 ones and vice versa. So they could both buy opposing controller but it would be a bit of waste of money buying a controller use like once.
http://www.gadgetlite.com/2008/08/01/co ... e-friends/
The good thing about Xbox controllers tho is that you can use them on your pc or laptop for other games , i tried using my ps3 one and had no joy , got an xbox one and it worked straight away