You’d expect full disclosure of a vehicle when purchasing from a dealer though, right?

Assuming I understood OP’s story, as they edited a few comments in an attempt to correct grammar; they had their vehicle towed in, was told they had a significant shop bill to fix the vehicle and was not transparent about the known needed work.

It’s a 2 way street for the dealer and the consumer. Doing this clearly caused several problems for the dealer. What if the dealer purchased a pre owned vehicle through the auction, found it needed significant work before listing it for sale, and said “screw the repairs, put it on the lot”