From my local tyre supply, Elmbridge in Swadlincote Derbys, paid £100 a corner which may not be the cheapest I just like the service I get from there good set of blokes.
Though... the original set they put on were the 'made in Thailand' ones (quoted at £90 a corner) check this thread for info Goodyears 'made in Thailand' they have just replaced them this morning for the proper UK spec ones which are either 'made in China' or 'made in Germany'. The 'made in Thailand' ones jesus did the car feel unstable they are a serious issue if you get offered gsd3s cheap then they will more than likely be the 'made in Thailand' ones.
I also emailed Goodyear direct and they said and I quote ' they (made in Thailand tyres) are not an authorised line in the UK'.
I disagree the side walls are soft on the goodyears and the grip is awesome I was running the standard fitment Bridgestone Potenza RE050s and the goodyears are cheaper and levels of grip in the dry are as good if not better.
Dan