I've found that two one-way car rentals from National are cheaper than a RT by any transportation service. If we stick to our plans to fly into Sanford, I've got a ressie for an economy car for one day, drop-off at Dolphin for $45. Going back, I get a car at Dolphin late the day before departure which I'll drop at SFB for the same price. For less than $100, and no gratuity, we get to and from the airport, taking as long as we like for a grocery (or other) stop. We're planning on staying at Swan or Dolphin but if that falls through we'll just drive to our WDW hotel, drop off the bags or check in, drive to Dolphin and drop the car then stroll to Epcot.
Bill From PA