Can't afford a disney trip, what to do to get to Disneyworld, please help?
Develop a taste for cornbread and beans.
Better yet, cultivate less expensive tastes all around. Sheesh. Must fly, can't drive? Living in the sort of neighborhood you'd be embarrassed to hold a garage sale in even if you have a need to? Need 3k on top of having lodging and flight already attended to? Can't delay a trip because "you like flying south for the winter?"
If your wife doesn't care enough about this trip to stick her neck out garage sale wise, and your kids don't care enough about it to offer up some of their surplus, then I'd say they've made it crystal clear they aren't interested. If this is one of those timeshare presentation deals, I can't say I blame them. And you can't figure out how to save or earn money generally without consulting a board that already has dozens of threads on exactly that topic without starting a thread of your very special own?
Ok, 3k in five months with an unwilling family:
1) Get a second job.
2) No eating out.
3) Have a "pioneer Christmas." (Put in some practice on developing less expensive and different priorities then, maybe.)
4) Sell your toys, you have no right to sell off your family's possessions if they aren't volunteering them in eagerness to attend this trip of yours already.
5) Pack a brown bag lunch and brew your own coffee.
6) Follow the family around turning off unused lights.
7) Offer to cook inexpensive family meals if your wife is usually the one that does the cooking (it might earn some good will, too).
8) Volunteer for handy man and similar jobs, like leaf raking, around your neighborhood.
9) Sell blood, or, hey, how about a kidney? That'll catch you up to the pack real fast, and you can get a GAC at WDW.
Or you could cut back on your plans for the trip, or you could delay or cancel this trip until it isn't such a burden to go. Either way, I would look into the deal you're getting very, very carefully before you get there. These things always have a bunch of hidden costs. Your $3k estimate may well be way off.