If £40 is all your willing to spend on a gun then the b2 is perfect for you. As the same with anything else if you want better quality you have to pay for it.
The b2 does what promised. It fires a pellet in a particular direction. What more could you expect for £40 new? However if you want to hunt with it I would suggest spending a little more. Even a brand new db4 is only £50 and a big step up