Yep... it's why nobody likes to use the Auction house--much. Either Barn finds or Junkyard for a lot of us players I imagine. I know that's the only places I go.

Only place I go is the Auction. Best place to buy in the game. You're trying to outbid competitors, so you're gonna pay over blue book.

Definitely great game.

It's OK to pass, my general rule is no more than 3 bids over EMV, this will be easily regained with car detailing and frame weld, for low health salvage yard cars, you're not going to make much profit on 3-5 star cars.
99% of the cars I get (out of ~1000) show profit (in the green) from the weld onwards.
It helps to have a fair idea of the final value of car at 100% (go take notes at Car Salon).

There is only two ways to lose money in this game, fluff a repair and poor impulse control.