Used car prices across the board are abnormally high. My own personal opinion is that it may actually take a couple years or so before things settle down to more historical levels. If you've followed any of the details around supply issues, particularly chips, in the transportation sector there are those suggesting the supply is not going to stablize and catch up to demand till end of 2022 at best.
Even if new car production gets back to normal around that time I expect that used car stocks will remain tight. This is due to have missed effectively a whole 2-3 cycle of new car purchases, so may still potentially be a shortage in late model used cars that persists for a couple years even after new cars sales come back to life.
So if you willing to wait on delivery of a new car at the moment, it could potentially be a good time to buy new, sell your old one. However if you're really in need of buying a used one, you may be on the short end of the stick for a few years. This situation hasn't motivated me to sell my mid 2016 MS90D with pano roof and free unlimited supercharging to get a new MS LR ... yet ... but I have to admit it has caused me to start pondering the idea.
Just my personal opinion.