If you can get someone to bring you to the Tampa airport, a one-day rental at Alamo from there to the Car Care Center on Disney property is under $70. Even if you only have 2 people, for $35 per person I doubt you'd find a better rate.
Alamo and National both have desks at the Car Care Center (they have a shuttle that will bring you anywhere on property after you drop off the car), and at the Dolphin (where you can walk to Epcot, Studios or the Epcot resorts)
-Rob