We are seeing the same thing all across the market. Prior to Covid, that was probably a $25-30k car. The B & E bodies have gone so crazy, the bottom of the market has gotten jerked up hard. Heck, folks are asking $20-30k for four doors & station wagons now. Go figure.
For comparison, a 23 Scat pack wide body challenger is about $50k. Can still get a manual. For the same price as the dart, you could get a nice used Hellcat. They are not an old vintage car, but there is not much of a comparison in my opinion.
I still like old cars, but at those prices, I think it is a better deal to go modern.