There is a city bus, Lynx but you must pick that up at the TTC. A taxi most likely would cost as much as a towncar.
Mears will pick you up a your resort and the cost per adult is aprox. $12.00 round trip.
You would need to make reservations with them, they will pick you up at your resort. When I called for information last year, they told me that I would need to call them about 2 hours before I want to leave the park for a pick up. I did not use them as I found out it was cheaper to rent a car for the day as there were 7 of us and I got a mini van for $45.00.