I suppose they must sell those pigs at some point or they would be out of business. It's not uncommon to see cars in poor condition listed for more than they are worth, look at almost any used car lot in any city. Uneducated buyers abound.
I was helping a friend buy a daily driver just after having moved to Austin myself and had a hard time finding a quality Previa to buy for myself, and the task of finding him a clean car for a reasonable price wasn't any easier. Shoddy or nonexistent maintenance that was obvious to me at a glance would be overlooked by a majority of buyers. Or I'm sure that's what the lot owners would hope. They certainly didn't seem too concerned about the flaws I pointed out. Private sales are the only way to go.
BHCC deals with collectable cars, ones that have curb appeal and collector status and I suppose some people don't like the hunt for that right car. I have bought cars in worse shape than some of the BHCC cars, but I paid very little for them, allowing me to buy the parts and invest the time needed to get them on the road. Paying their 'finder's fee' via their high prices and then having to restore the cars is just nuts. But for the check book restoration crowd, it's a way of getting the car that they want. For some, paying a lot for something just gives them something else to brag about.
Ian