It is always an interesting topic regarding car prices.
I suppose it is very hard to put an exact figure on cars values.
In my opinion it all comes down to what you want and if you are prepared to spend.
This also effects lots of other items for sale, houses, artwork and etc.
We all prob know somebody who has paid a ridiculous amount for a "toy" be it a motor cycle, classic car, boat, shack or holiday home and if you think about it if you really enjoy the use or your "hobby" or "interest" and you can afford it then go for it.
I think the value of nice classic cars are on the rise again after the bubble burst a few years ago.
Regarding the price of GT V6's, I was in the market for a nice one for a few years and the advertised ones below 20K still needed repairs so it is hard to put a price on them going off recent sales.
Again only my opinion and the car in response to this thread does look nice.