I became frustrated when shopping for a card that wasn't prohibitively expensive or sold out but had decent Mh/s performance. Thus, I created http://bitrigs.com
. The site allows you to sort ATI cards by performance, power usage, performance per dollar and power usage per dollar. At the moment it just links to newegg.com but I'm in the process of adding amazon.com. One of the nice things about the site is I've hooked it into the product databases and it updates about once every 3 hours for the latest prices.
Please let me know if you have any suggestions for the site