You may find some of the condo hotels on I-Drive what you are looking for - perhaps Floridays but sorry I don't know how much they are
Other than that you may need to look slightly further away. We are currently in Kissimmee and about 15 mins from Seaworld and 20-25 from Universal - always depending on the traffic and how fast you drive If you are wanting to be that far away you will find some nice new resorts within your price range.
Marriott's Horizons Resort would be great with kids. They have a pirate ship in the pool area. Their Grande Vista Resort is also beautifu. Not sure what the prices are when you would be going. But both are near SeaWorld and only a short drive to Universal.
Hi. Have you ever used www.vrbo.com (vacation rental by owner)? We use them every time we travel. We have stayed at Windsor Palms and love it. The same developers have opened a new place called Vista Cay. It is 3 miles from Universal. There is a very nice pool, clubhouse, tennis, etc. and you can get a nice condo or townhouse with a full kitchen and all the other amenities. It is much more economical than the hotels. You might also check out Windsor Hills, which is also from the same developers. The two Windsors are really nice, but they're closer to Disney than Universal. If you go to vrbo.com, click on Florida and then Orlando. You'll see "Vista Cay" in alot of the titles. If you want to look at the Windsors, go to Kissimmee instead of Orlando. Good luck and let me know if I can answer any questions for you.
Laura