these are mine, a set of front and rears (although the rears a rarely coilovers but are springs on height adjustable purches, unless you buy GAS or similar), they cost about 400 quid but were from a company trying to get me to be a supplier so they were cheap - plus they threw in a cat so i could not refuse! So 250 quid for a set that are welded and the right set/height up are worth every penny, a new set like mine will set you back 50-100 for decent welding all day long, and its not something i would give to a birdsh1t welder.
welded up:
and on the car
and after many hours just about set up with a 35-40mm drop
dont forget to budget quite a few hours of set up, they will be on and off more times that a whores knickers before you get them right!
i would say 250 quid is a good price.