You may want to do what I did last year. I called Mears. They have the towncar service and they have the taxi service. I spoke with the towncar area and got a price quote. Then I had them transfer me to the taxi division and got a price quote form them.
For where we were going, the towncar was quoted at a cheaper price! But I passed. Even the towncar was going to run $50.
I also called WDW and found out we could have taken a bus from the TTC (Bus #51?) to Sea World.
It has been over a year I called and got this information. So you would want to get up to date info. But it gives you some ideas. From Sea World you can even take a trolley up and down I-Drive.