So so far we have the following prices inc vat, fully delivered for Toyo T1-R's (just as an idea). I've included the non-fitted price too as some places don't provide a fitting service:

Site..........................Price Fitted.......Price Not-Fitted

Blackcircles.com..............£313.68............£265.58
Tyreshopper.co.uk............£341.20............N/A
Camskill.co.uk.................N/A..................£277.04
eba_y_tyre.store (ebay)...N/A..................£283.00
Topgearshop (ebay).........N/A..................£284.00
Allnewtyres.co.uk.............N/A.................£290.16

Is anybody able to beat those prices?