No one's saying base cars are going to be in the 50s unless they're, salvage title, uber high mileage and/or worn. I'm the most glass half empty person here and even I think they'll settle into the high 60, low 70 range. Outside of some desperate fire sale, 50s is a way off. I'm just being realistic. BaT and these big swinging dick auctions are usually inflated due to the bidding nature of them, Mecum and BJ more about swinging your weenie around + lots of alcohol. A dealership in the middle of Iowa isn't going to pull Mecum numbers. The question is: what's the inflation factor of your car being on BaT? 10%? If so, then knock that off whatever the sold price is for "regular", lot lizard cars. I wish I had access to Mannheim auction info because that's where the real numbers are. COVID, PPP, overinflated RE values and crazy amounts of stimulus messed up the car market. This is a short term phenomenon.
Also, when production was stopped on S197 GT500s, values trended downward, albeit slowly, and continued to do so until COVID. I see no reason what that would be any different here.