In the 30 plus years I've owned a Pantera, Pantera owners have always claimed the cars are way underpriced. Then when the price starts to go up, they complain that they are getting too expensive for us "average Joe" owners.
IMHO, it would be nice to see some appreciation; it would help justify some of the cost of restoring the cars which, in turn, would help keep our vendors going, etc.
The truth for me, and probably for most of us, is that I love the car in spite of, and because of, its faults. I don't want a Z06 or a Viper. In real dollars, my car is probably only worth, today, about as much as I paid for it way back when. This means all the money I've spent restoring/maintaining/insuring the car is an unrecovered cost. But I don't care, I plan to keep driving mine for as long as it takes for prices to go up.