Richard---
As usual, depends on condition, completeness, which versions you have, etc.:
- there are at least 2 or 3 versions of the boxed set, some of which were shrinkwrapped, but most of which weren't; most of the earlier boxed sets had a map that was truncated, too---you can see the differences in the two maps on my FB page at
https://www.facebook.com/grodog/media_s ... 831&type=3- there are at least 3 versions of Dark Chateau (d20 original, CZ version with 2 different pieces of cover art)
- so far as I recall, there was only 1 version of Yggsburgh printed, and it was issued with a color map insert bound in at the back of the book, too
The most-recent sales I've seen have been on various Facebook groups. IIRC one just sold with a blown lid (quite common in the boxed sets) for $250-ish.
Post some pics and we'll help you nail down the details!
Allan.