£3o in shops for PC
£6o in Steam for PC
I THINK! Well, I bought from Game for £3o and in Steam its £4o-£6o
That was already said, Steam offers games for higher price, the only thing you don't have to worry about is that they won't sell every of it so you don't have to wait for the next shipment.
But you do have to dload it which is long for someone with lame internet.