My advice...GO. We have 4 kids,and always drive to save $ and to be able to take all of our "stuff" with us. The trick to making this a reality is to get your kids involved; they are old enough and it is THEIR vacation, too. We went right after Easter, and the Easter Bunny filled their baskets with lots of goodies for the trip: 20 Disney dollars each, a fanny pack($5 at
Walmart
w/water bottle), and snacks to fit into the fanny pack. The kids knew we would be eating breakfast in the room most days, and we made a list of what we needed and bought it before we left(we pack our cooler with the food, then unpack it at the resort and fill it with ice and a gallon of milk). I brought our own water and filled the water bottles, and limited the kids to one snack item per day at the parks(usually a Mickey Bar)that we budgeted for. After poring over menus at Deb Wills' site, we decided which restaurants to visit and which day to do each park(if staying offsite, the park that had EE the day before is a good strategy). We put the $ for each day in an envelope and put my oldest(then 10)in charge of keeping track of what we spent(it was her math assignment since we were missing school). She was very good at telling the younger children "no, we did not bring $ for that", which only happened twice in 5 days...they were too busy to shop most days. We planned one full day at the resort to swim, and one full day at Downtown Disney(your 6-year-old will really like Legoland). To get the max out of the park for the day's admission price, we ate a sit-down lunch(cheaper than dinner) and a counter-service type dinner, and planned a little down time somewhere in the park in the afternoon(a show, water area, etc.) I took a backpack to MK and Epcot with their swimsuits, and ziploc bags to put them in when we were done playing in the fountains. We brought our own double stroller for the 2 youngest, and kept neccessities for the day in it. Each child wore their own fanny pack, which contained an autograph book, a pen, sunglasses, cheap poncho($1 at walmart),and snacks. They helped plan the whole trip, and loved it! We have been lots of times since then, and spent lots more $, but that first trip was so special because they were involved in the planning. I really think you can do it! Good luck!