Are you starting airsoft? Because if you are, I'd suggest actually going along to a few skirmishes and getting a feel for the hobby, if you don't like it and you splash £250 out on a gun, you'd feel a little stupid. Also skirmishes are a good way of seeing what everybody's got and seeing what you want/don't want.
As a starter it'd be advisable to get a gun around the £150 mark so you can buy some boots, decent eye protection, camo and a chest rig or assault vest