I think those prices are fair. All Adversary games items are very rare.
That is the only second copy of Red Book of Nal and Sword & Shield that I have ever seen - I don't have these ones but I do have a pdf of Sword & Shield.
Asphodel Inn is slightly less rare since I have had 4 or 5 pass through my hands (and have seen 1 other copy on Ebay before). I tracked down Carl a while back and bought the remainder of his old stock. Yes it is the same Carl Smith as N2 - he also did some Pacesetter items too.
A near complete list of Adversary Games items is up on the Tome of Treasures (missing only 1 or 2 items):
http://tomeoftreasures.com/forum/viewforum.php?f=198