I sold my GTV 3 years ago. I sold my Teledials separatley to get the most money I could for the car. They don't really add value to a car. I got £660 for them on ebay. They all had a few scrapes to them, but generally in good condition, but definitely not mint. They had two half worn pirelli's, an almost new Eagle F1 and and a newish Avon ZZ3. So not even a matched set of tyres.
I didn't think they were worth that at all, I was quite shocked.
I sold the car with standard wheels that my mate gave me in exchange for buying and fitting some lowering springs to his GTV.
He has teledials on his GTV, he bought them off ebay £360 inc delivery with bald tyres, then spent a fortune on a set of Eagle F1's for them.
My P2 GTV TS came with Teledials. It had one lady owner, and done 27k. They must have been fitted as an option from new. I paid no more than comparable cars at the time with standard wheels so I was well chuffed when I got it.
AutoLusso generally sell them for £600 with a set of good tyres, so on a private sale I would agree with Mr_Caine - around £450-500 with decent tyres.
I guess it depends on how many people are looking for them at the time and how much they want them... and how deep their pockets are!