TCGPlayer Seller Aggregation
A Firefox browser extension for TCGPlayer.com
Identifies the fewest (non-direct) sellers needed to purchase all cards
Adds a "add to virtual cart" button to every page, right below the big blue "add to cart" buttom.
View virtual cart by clicking extension icon.
Once all cards are present, hit aggregate to get the top list of sellers for each card, and how many of your cards that merchant has.
The merchant price is listed, as well as the lowest price available amongst all merchants (not just the ones listed in the extension) (damaged quality cards are excluded).
Clicking the merchant name will open the merchant profile so you can see there location and reviews.
Clicking the card name will bring you to the product page for that card.
Clicking add to cart will obviously do that, but you may need to refresh the page for it to show up.