Wow Myles,
That's some serious money!
One pretty interesting thing is checking the sellers feedback. Almost all the "winners" of these jazz classic originals are return customers. They must all be satisfied with their purchases so at least the records must really be mint as the seller states. I guess if I was in the position to pay that kind of money, I'd be glad that there was a seller on eBay that deals in actual mint condition records like this.
Heck, and some of the 1500 series Blue Notes sold for less than $1k!
If you look past the first page of feedback, there was a Sax Colossus that went for $2850.