[father of 3]

When it comes to new cars, everyone wants to know dealer invoice, incentives, etc. Once this is known, haggling over a "reasonable" profit ensues.

But, if you plan to buy used, knowing what the dealer paid is much tougher (correct?).

Hypothetically speaking, if you did know how much a dealer paid for a used vehicle (trade-in or auction), what is a "reasonable" profit margin? Dealers seem to want much larger profits on their used vehicles. Your thoughts on this are appreciated.