I haven't seen it at a cheaper price before. I have got this hard drive already, it has never given me any problems. Ryman gives you free next day delivery/c+c options on all orders above £30.
My local Ryman was out of stock when I checked yesterday, but stock is available online.
I dont use cashback personally, but TCB says it gives 9.2% on Ryman online orders - best confirm for yourselves.