Not quite in the area of Disney but not as far as Tampa, a day at LegoLand, Florida might do the trick, especially if you have kids who simply can't get enough of the plastic bricks.
A one-day ticket will run you around $79.00 if you catch them on sale but they tend to have sales all the time. The price for a two day ticket could run around $104.00 which considerably cuts your $74.00 single day price to just over $50.00.
There are several parks to choose from at LegoLand as well. The new Peppa Pig park and a water park as well.
LegoLand offers Lego themed attractions that are designed and suite for children. In fact, I'm not sure there is any ride at LegoLand that isn't rideable for younger guests.
LegoLand typically isn't the draw near Orlando as you will need to travel a bit south to Winter Haven.