I'll give you a compromise.
North airport exit, left at first light (Frontage). Little over a mile to next light (Conway), left and left again at lights to get on 528 (Beach Line) West.
Since you want to save money, be careful here, keeping to the right and going down what looks like an exit ramp to pay one toll (75 cents last time I went there). You then return to 528 and at the end take I-4 west (southwest). Disney exits will appear in due time.
Returning to airport via I-4 East to 528 east, again watch for the toll ramp off to the right on 528. Get off 528 at its exit 9 (Tradeport). Left (north) and cross under. Get into middle lane. Required right (east) onto McCoy, little over a mile is 436 (Semoran). Turn right to enter airport.
Having read various complaints about exact change tolls not registering, I suggest using the manned toll booth when paying cash, and asking for a receipt.