Good price for what you are getting. The CPU alone hits the £200 and up as new and is known to give a solid OC speed of 4.40GHz.
Just make sure the mobo is a decent one as a lot of these deals have absolutely pants mobo's fitted, and got any more details on the GPU as depending on who's it is (ASUS, Gainward etc etc ) it varies in abilities.
Also ditch the case and PSU as they will cause you problems if you try to run games and intense applications at full throttle.
If you have another £100, you can get a decent case and PSU that will last you a long time.
Google CCL if you want to have a browse through some kit. They have been in the PC scene since day one virtually, and are still going strong.
I have used them again and again with my builds over the last 20 years and I have had no problem with service or wrong info from them