If you were thinking of a taxi it would be cheaper to catch the resort bus to DTD then get a taxi, as opposed to catching one at POR.
Cheaper option would be to go via the mears shuttle bus, POR can call them for you, approx $14 return trip(they also go to seaworld), it does pick up at other hotels, but this doesnt add on much extra time, if you catch the earlier pickup time.
OR
If there are a few of you get a indepedant travel company, like ***********, where you pay via the car not per person.
Jules