I have just fitted PR3's and they are without doubt the best tyres I have used.
I've been through 2CT's, S20's, 023's in the last couple of years and the PR3's are superlative for the road.
I got mine from Challenge in Salisbury for £248 ride in ride out.

Chippenham Challenge fit bike tyres too (if Salisbury is too far)

I was quoted £302 and £286 at other dealers and decided to save the £38 as I had to virtually pass Salisbury on the way home one night.