The thing is though, in my eyes, the R34 GTR is not a spectacularly special car, there's nothing that significantly sets it apart from its previous iterations. Some would say, it's little more than a poor man's Porsche. I don't like its design and its engine and drive train is inferior to the 2JZ and its drive train. So although I am not placed to argue its value, I cannot justify the disparity between it and the Supra.
Whilst you are correct in saying that 20-30 members though, perhaps more notably, owners, publicly criticising the hike in value, of an asset that they themselves own, will not hurt the market in the long run. This however, will affect the market in the short term by serving to cause hesitation and uncertainty.