I posted this over on The Chat too, but in case anyone over here wants to kick the tires:
I've been working on a spreadsheet to help figure out the total savings for the process of buying discounted Target Gift Cards at Raise.com and then using them to buy discounted Disney GCs at Target.
You can enter how much money you need to pay Disney, the maximum size of the gift cards you want to buy at each site, and the percentage discounts. (All in the Yellow cells.)
It will tell you how many of each card type & denomination to buy & tell you how much you saved, as well as how much money will be left on the last Disney card.
It is on Google Sheets here: http://ow.ly/PXQ1m
(BTW, I've locked down everything except those yellow cells so no mistaken shenanigans with my formulas. Anyone can make a copy for their own use...)