FW cabins are more expensive then getting connecting value rooms or a vale suite, bt the full kitchen might afford you the option of saving a lot of money on food. 2 adults and 6 kids, even a single counter service meal could get over 50 bucks. There are local markets that will deliver groceries. Plan some "at home meals" (even if it's simple stuff like pasta or pizzas, cold cut lunches, cereal muffins & fruit for breakfasts) and stock up on snacks, too. It still might not be the bare-bones cheapest option, but maybe just maybe a more pleasurable one, a dfferent type of WDW vacation than what you might be used to, and one you'd really like. More things for families to do there, the campfires, the movies, ust playing basketball or tennis. And of course, there's something really neat about having ferry service to MK.
I know it's not the answer you were looking for, and I certainly understand the desire and/or need to cut costs. I hope my suggestion isn't as jerky as "Aw, go for a 2 br villa at beach club and charge it, to hell with tomorrow haw de haw haw, that's what rotating credit is for." I just happen to think there's a value in the FW cabins that goes beyond dollars and cents, and there's plenty of opportunities to make one work within one's budget. The cabin would probably be like $70 more a night, but if you could average a savings of 50 bucks a night by using the kitchen, you've possibly got a much nicer homier, familial vacation for only 20 more a night. Looking on this board alone, I see FAR more unpleasant experience comments with value resorts then I do FW cabins. Granted, there are more value rooms than FW cabins, so the ratio of negative comments may still be proportionate. But with so many stories of school groups, youth tour groups, & athletic groups acting like barely-chaperoned zoo animals at value resorts, paying more for a cabin and balancing it out with "home-cooked meals" would certainly appeal to me. Just throwing it out there.