Just overpaid on a Lexus RX350 and sold my 2019 Honda Accord LX to CarMax.
Basically got back all my lease payments over last 20 months - $4,500
Carmax is buying about 30 cars a day at my retail center.
Based on my observations, I think CarMax is banking on a protracted shortage of vehicles.
Worker there told me they are buying more than they are selling, but are still making money. (I guess net of auctions).
This seems like a toilet paper effect. In my market deals seem hard to find, so I just may end up buying a Tesla Model 3.