I saw this for £6 instore at CeX.
Great game and well worth £6.
There is additional P&P when buying online (which isn't recommended at CeX anyway).
This is preowned and the condition varies but PS3 game are very durable.
Link to site to prove price:
Tesco seem to give £6.50 vouchers for this as well, if you're into that kind of thing: