I went through my trip stuff;
Gas $235 (just a shade over 2700 miles, at 33 MPG)
Accomodations $185 one night Dalton, GA going down, and Corbin, Ky return
Meals $100, both hotels provided breakfast, and we packed snacks, so two suppers and a lunch were purchased.
Tolls were $9.50
Total $519.50
Tickets to fly out of Detroit would have been $880
gas to airport $30
Hotel $120
Parking $50
Meals $70
Tolls $5
Total $1155
We used the $635.50 for an extra 4 nights there, and souveners.
We leave at 4am, and have been at Disney by lunch day 2, so it is a half day lost. We leave WDW at 8am, and are home by supper day 2, so it is a day lost. We drive an SUV as well and get 33 MPG. From Toronto to WDW is 1303 miles, at even 20 MPG this is 65 gallons each way, or $400 for gas round trip. Figure $325 at most to drive. Flying is a convenience, but it is not cheaper, unless it is a family of three or less.