If you want a 1st edition 1st print of any of the TSA books, or Advanced Reader Copies / Uncorrected Proof, I assure you they are out there.
That said, I sometimes run across good deals so I figured I'd share the information by posting it in this thread.
Some potentially useful information to the aspiring Bakker collector:
Things like 1st/1st of TDTCB in great condition often show up for around $80. More than that and you're better off looking some more. Less than that, and you'll want to make sure you are getting what you think you're buying. 1st edition 2nd printing (missing the '1' from the numberline) will go as low as a few bucks, up to over $100+. You'll be disappointed if you get a 1st/2nd and paid full price for it (Overlook printed the 2nd prints on bad paper, so they are already heavily yellowed, and have printing stains on them.)
TWP 1st/1st tend to be a bit less expensive, but can be harder to find. Generally they are priced cheaper than TDTCB. Maybe $50.
TTT, as far as I can tell, they only did 1 print run, and while lots of them have been remaindered (black mark on the pages at the bottom in sharpie), they are generally not too difficult to find and shouldn't be too pricey. You should expect to pay more for one that isn't remaindered.
TJE and TWP probably only have 1 print run as well, and should be pretty easy to find given their publication date. They should cost about what a new hardcover costs.
If you are interested in purchasing a 1st/1st of TDTCB you can PM me, I might have an extra one or two laying around that I could sell you.
Advanced Reader Copies (ARCs) and/or Uncorrected Proofs:
All the Prince of Nothing books have Uncorrected Proof editions. These are softcover, published by Penguin, and while not particularly prolific, tend to sell fairly cheaply, maybe $30 or less for each. They can be difficult to come by, and I've seen prices increase over time.
It looks like Overlook switched from "Uncorrected Proof" to ARC after PON. I have never seen an 'Uncorrected Proof' of TJE, but if you find one let me know. ARCs do exist and tend to be more expensive than their PoN counterparts. The two ARCs that I have seen were published by Overlook. Softcover.
WLW has Uncorrected Proofs as well, and at least when I was looking, was easier to find and cheaper than the TJE ARC. Published by Overlook. Softcover
Might be noteworthy for the completionist/OCD in you, that there is a press release sent along with each. Its just a piece of paper that has a synopsis of Bakker's books and its printed on an Overlook letterhead.