I've since discovered that there were only 58 P3 GTV V6's registered in the UK before production ceased. They're rare things indeed.
This explains why I never see any for sale, and also why they command a far higher premium. Aesthetics are of course objective but I much prefer the P3 nose overall.
It presents a dilemma for me because If the P3's are going to cost in the region of £10k (assuming I'm lucky enough to find one for sale), is my preference for the facelift nose really worth an extra £4k over, say, a P2 Cup? Probably not.
Yes you could argue that you also get the 3.2 V6 and an extra 20bhp with the P3 but in the real world that mild performance improvement in performance doesn't mean much to me.