I know you can buy discounted passes at Company D stores, but what kind of passes? I have a lot of family coming down over Christmas and a few other guests coming throughout my stay, so my 6 day free entry for them would be up pretty quick.
I'm pretty sure that you can get any of the Magic Your Way tickets at Company D for a small discount. It's nothing huge (the discount rate is about the same as the sales tax rate), but it is cheaper than buying them at the gate. I'm not sure if it's cheaper than AAA/Disney Store. Check with Company D for a price list.
Edit: Check the Hub/Portal under "Disney Difference." Scroll down to the "Cast Members Only" module. Under the Company D heading is a link to the full range of Cast Discount Tickets.