In my experience a car from a yard has 5k added to it compared to private sales price, lots of people buy card and cannot keep up maintainance, servicing and rego, these are the cars you look at and low ball them, they need the money, you've got the money, its a match made in heaven.
A lot of the trouble comes from people thinking they can get what they paid for it, it rarely will happen, no matter what people think in the end its only a car which is getting cheaper by the day.
Shop smart, shop S Mart.