Here's a screenshot of the upcoming deck pricing feature. We are currently working on optimizing the screen, as it is quite processor intensive. 

An interesting feature we are testing out is having the deck pricing automatically find the lowest price possible for the deck, by scanning through every version of a card. For example, if you added an Alpha Giant Growth into your deck, the deck price would actually report the cheapest possible Giant Growth to buy, i.e. the Magic 2011 version.