it depends on who's at the auction man.
if a car doesnt meet the reserve, and fails at an auction, then only after that im able to privately sell.
as an example(not factual figures) a c63 new ranges at around $180,000 drive away(including finance and stuff +say 30% interest)
we sold one that was a 2011 face lifted model c63 amg done 12,xxx k's full service hist, rwc, 1 year rego blah blah blah, for about $110,000