cheapest ive seen are black diamond cross drilled and grooved from jondel motorsport (08007313934) for £130 and a set of 4wd pads are £50 but you get a £6 discount if you buy both together and its free p+p. I just got black diamond discs from jamsport in northampton but cost more expensive because i went for the ebc red stuff pads which were nearly £80. 4X4 cosworth pads are well expensive the only downside to having the set up dont know why they are expensive they look the same as any other pads