this site is great, my one thought is to add a function for totaling the value of all cards in a collection. i think its a relatively easy addition, everyone likes to know what there collection is worth and watch its value fluctuate based on the small fluctuations of individual cards
Already exists.
Go to "Inventory" and you have the "View" menu (right, up), where you have "Show Value" option. Your inventory is worth "$115.76 (using the average price on tcgplayer.com)" :P.
You can actually do this for the "Tradelist" and "Wishlist" also.