Circuit City and Best Buy are completely worthless. Every once in a while I find something I don't have on Amazon, and that is my main source now. I probably own about 70% of all the classical music that has ever been released as DVD-Audio or SACD, but it's such a boutique product that no one does a good job of keeping it in stock or notifying me of new titles. I end up looking at the web sites for various labels that make HD discs (e.g. Telarc).
Also, DVDA sounds dirty to me, too.