could you and hubby miss a Friday at work? If not then a flight returning the next day could be very expensive. It may not be worth it. But if you can include a Saturday on your stay, you might be able to swing it. Here's a few suggestions to ponder over and research....
1.) Pick a time during the value season to go. First reason is because the crowds are light to moderate. You can get more done in less time. Second, if you must stay on site it's cheaper.
2.) Check each individual airline website that services your area often. (Atleast wkly)Sometimes they have unadvertised web fares.) Also watch the Snooze you lose board for cheap rates.
3.)If you study TravelSheryl's Priceline board and staying on site isn't important to you , you could get a room and car for 2 days for less than $100.00 But remember you would be off site.
4.)Watch the DVC rent/trade board and this board. Sometimes DVC members give points that are getting ready to expire away. For as little as 16 points you could do 2 days on site. Also sometimes people give away their Priceline reservations.
5.)Research ticket options. Would it be better to get a 2 or 3 day pass or 1 day tickets w/ bounce back? What about the discount 1 day tickets at Walmart?
You got your work cut out. Not including airline tickets I would try to keep car,hotel and tickets under the TOTAL price of 700.00 Keeping a change jar, banking the money you save by using coupons, having garage sales, selling items in ebay, doing rewards programs, etc...will help out alot. I say go for it. And remember planning can be alot of fun also. Good luck!