bike-discounts.de is the place to go. They have them for just over £23 each, and £5 delivery. So you can get a pair for just over £50 delivered.
I have a set of these on my bike and they are excellent too. By far the best all weather tyres you can get.http://www.bike-discount.de/shop/k373/a798/grand-prix-4-season-23-mm.html
Is 622 std size ?