I've heard only good reviews about Pristine too. I'd be wary of anything too cheap, £55 sounds very cheap. My dealer (or rather the body shop they use) quoted me £115 per wheel for diamond cut refurb. Lepsons come in at £80 each (19") so I'll go with them when I get round to it. They're 35 miles away, so not too far.
If you want a decent job doing, it will take a few days.