How do you get discounted Disney gift cards??
I believe there is a dedicated thread somewhere for Disney Gift Cards. I specifically use my AmEx Blue Cash (the old version) credit card to buy Disney Gift Cards at Safeway (if you're not from the West Coast, this is a large grocery store chain here). My credit card gives me 5% cashback at grocery stores, and you also get Gas credits from Safeway worth about 3% (for me anyway, you can stretch them out a lot more but it's a lot of hassle). I believe you can buy them on BJs at
http://www.bjs.com/1---disney-gift-card.product.287853 . $95 for $100 card with free shipping for a 5% discount, and last I heard it doesn't require a membership. In addition, you get 1% cashback there from ebates and also whatever rewards you get from your credit card. There are some other options as well, you can look for the thread.
I'm always stocking up on Disney Gift Cards to pay for tickets as well as any food/merchandise for our trips, and even use them to pay for DVC Annual Dues.
Edit: here is the Disney Gift Card thread
https://www.disboards.com/threads/disney-gift-card-deals.2941964/ . You may have to start at the end and go backwards though, because many of the older techniques are no longer working (like Target RedCard).
Edit #2: If you really want to go a step further, you can open a Disney Vacation Account and deposit your Disney Gift Cards into your DVA, then use your DVA to purchase your tickets. DVA gives you an extra 2% back in the form of Disney Gift Cards, but it has to be open for at least 6 months.