I pay for all my cruises with Disney gift cards. My budget is really tight so here's my strategy.
1) pay with gift cards (saved 30% doing this for my August cruise)
2) swagbucks-- since end of June I've been able to buy $1550 in Disney gift cards using my swagbucks earnings. This is covering photo disk, excursions, tips, souvenirs, placeholder booking, etc.
3) shopkick for my kids' souvenir money
4) used a TA. Cash back will cover hotel and parking at the port
5) used the dreaded DVA (you can call
dcl and pay directly even if you use a ta). The bonus I got covers one night at pop century pre cruise (we had left over no expiration tickets).
I think my total out of pocket for 7 nights on the Fantasy with my two children will be $3,000.