mcweaver, I've heard that they improved the game design and added some things in Ashardalon, and they seem to improve and add new things in the upcoming Legends of Drizzt. Though I have only played WoA so I can't speak for CR.
Calimero, I don't know , I bought mine in a Swedish brick&mortar store for 500SEK which is 77USD. You can probably find it cheaper if you look. Though 500SEK is the standard price for most boardgames here in Sweden. The difference is that you get a load of components in this game which increases the value for money factor by a few notches. It seem to include as much stuff as Descent, but it was 300SEK cheaper.