Youll be glad you dont have a mini cooper .... last set for the wifes car £1100, There down in price these days but I about laid an egg...
Have you tried... http://www.tyresonthedrive.com/search/ I need two new fronts on the Toyota, that's who I'll be getting them from. A couple of peeps on VZi have used them and give good reports.
We've just changed our car from the new beetle cab with are about £150 a tyre from a garage to a Citroën c1 which is £125 for a set off 4 from a garage, I don't get my tyres from a garage I get them through a mate who fits them for me a fair bit cheaper than a garage.
I did that for a MK1 Transit minibus I had, after a year I had a matching set of Uniroyals with go anywhere tread. Within a week of getting the last one someone slashed 2 of them with a stanley knife.
As has been said above - black circles or tyres on the drive - they come in at about 50 quid each in the size you've quoted, that's £100 less than you thought. Tyres on the drive are excellent - 2 hour window and they come to you and do all the work, all you have to do is pay them when they're done. No more schlepping to the tyre place and sitting in their waiting room.
I know where you're coming from I had a set of 18" john cooper works split rims on my cooper and nearly had a heart attack when I priced up a set for mine
Yeah always look at wet grip and fuel efficiency now as well. The ones I linked to above are B for both.