The second hand market in the US is insane. I don't know if it's Abe or profiteering, but it's completely normal now for small-run books which were in print for $10-$20 to go on sale on the used market for $100-$200 as soon as the print run ends.

There are at least four books I'd quite like to own which have been out of print for a while now, and the lowest asking price is $135. I had one in my wishlist and when it was still in print it was priced at a more usual £9.

You can see this on Amazon marketplace in the UK, which includes US sellers - they'll typically charge four times or upwards of the UK marketplace prices for items which are easy to find.