First, asking price is not market price. But the used car market is strong these days. And that is mainly because new car prices are too unobtainable for the average consumer, and new car manufacturers have overestimated what kind of technology motorists want. And it's that technology that the consumers are paying for.
And today's used cars are much more durable than what used cars used to be. The Crown Vic, for instance, can last 500K miles if it's really taken care of.
Still, I bet you can offer less than half, and still close on the cars you're looking at.