The current exact price is $59.00 per day plus tax. With tax, the total cost per day is $62.84.
And, as Clkelley pointed out, a day doesn't mean 24 hours. You actually get a little less. Pick-up is after 1 pm, and return is by no later than 11 am the next day. You can possibly pick up the cart early, but the 11 am return time is not flexible. If you keep the cart past 11, you pay for another day.
You can and should reserve a cart for the day you are interested by calling the Bike Barn at 1-407-824-2742 (choose option #5). They take a credit card to hold the reservation, but do not charge the card. I am not 100% clear on the cancellation policy. My personal experience has been that you can cancel the reservation with no charge at any time up to and including the day you are supposed to pick up the cart, but I am not sure if that is official policy, or if I just had a nice castmember.
TCD