Atlas Games has reported that they've reprinted Tomb of the Lich Lord and it will be in stores soon. This item has been unavailable for some time now and I'm glad to see it back in stock because it is as close to a "base set" as Dungeoneer has. Though all Dungeoneer sets can be played alone or combined with other sets.
So don't pay any more for it then retail price. (Unless of course you want to support this site and get a signed copy along with original art)
I don't think any changes have been made to the cards, but it is likely to have the latest rules in it (v2.3).