You don't always get what you pay for tbh. I bet snap-on/Halfords have a much higher profit percentage than the cheaper tools brands.....or they wouldn't be able to reduce them so often and make lifetime guarantees. 
I have a 'Phaze' cheap socket set, cost about £15 iirc from Halfords, bought just to keep in the car as it's small and light......but I use it for most jobs tbh!! Previous one I had for 3 years before I finally broke one piece - the reducer for smaller sockets, but then again I was removing brake caliper bolts lol. Bought another set in the sale for a tenner and haven't broken anything in that one for over a year now....
I do have a Halfords pro kit as well, but only really use it for heavy suspension work or similar.
I have a 'Phaze' cheap socket set, cost about £15 iirc from Halfords, bought just to keep in the car as it's small and light......but I use it for most jobs tbh!! Previous one I had for 3 years before I finally broke one piece - the reducer for smaller sockets, but then again I was removing brake caliper bolts lol. Bought another set in the sale for a tenner and haven't broken anything in that one for over a year now....
I do have a Halfords pro kit as well, but only really use it for heavy suspension work or similar.