The Disney Resorts are definitely not budget but you can stay at a variety of other hotels that are right across the street and a 5 minute walk from the gate. These run about $100 per night and if you can get the entertainment book rate at the howard johnsons that runs $59 and $69 per night depending on what view you want. That walk is a little longer but still walkable.
We've stayed at the Carousel Inn. Nothing special but it's close, offers a small cont. breakfast and a place to sleep. Park Vue Inn is a step up from Carousel, even closer and again nothing special. You are paying for the convenience to park. Others you might want to check out are Best Western Park Place Inn, Tropicana and the Candy Cane Inn is well liked although I've never stayed there. These all have websites so you can look up rates.
Good luck!