I agree the amount of fun you have with these cars is partially due too some good tires.
Also due to the average size of the alloys we use on these cars the tires are not that expensive at all to begin with.
And due to the high amount of cars that use the same sizes there is allot of competition aswell wich lowers the price even more
I use Vredestein Sportrac 3 tires, very very good grip in the dry but there even more impressive in the wet/damp/moist conditions (10000x better than toyo's t1r in these conditions).
The toyo's are probably a bit better on the dry but for an allrounder the vredesteins are outstanding and definatelly get my vote !
The Vredesteins are probably a bit more uncommen in the UK but here thet are rather popular (bang for buck = realy realy good)
Got 4 of these in 195/45/16 for 300 Euros (260 pounds ?) a few months back.
Check :
http://www.tyrereviews.co.uk/