Would you be willing to do uber and lyft rather than a shuttle? It's so easy to use these driver services in Orlando, and pickups are practically instantaneous. That opens up so many possibilities, and the savings you would receive getting a place without a shuttle would easily pay for the uber/lyft costs.
We, for Christmas for example are coming up to see family Dec. 21-25 and are able to get two bedroom/two bath condo at Cypress Pointe for base rates of $97 a night with AAA discount, $108 a night plus taxes non refundable if you don't have one of the cards that do the discount, or $144 a night refundable etc. There is a nice warm themed pool, playground, tennis, game room, etc. You get a screened in balcony with table and chair for sitting out, kitchen - living room - dining room area, large master suite, smaller bedroom, two baths, washer and dryer. There is a pull out bed too, so this place sleeps six. The location is very close to the entrance of downtown Disney, so there are lots of restaurants nearby. This is just one of so many possibilities, but was an economical option we just booked last week. Less popular dates have even lower costs.
Diamond Resorts site
https://www.diamondresortsandhotels.com/Resorts/Cypress-Pointe-Resort
Oyster - a favorite site of mine for photos
https://www.oyster.com/orlando/hotels/cypress-pointe-resort/photos/
Renting for a full week from a timeshare owner is even less expensive, but we are doing just a four night stay, and those rentals on sites like Redweek.com or TUG2.net are for seven night Fri - Fri, Sat - Sat, or Sun - Sun stays.