You can go on the Uber app, type in your start and end location, and it will give you a range the fare will be in. I've used Uber with great success in Atlanta and was planning on using it while in WDW, but was put off when I arrived at the airport and saw numerous signs advising against Uber. From my understanding, Orlando is one of the cities that is very against the service and trying to get it outlawed. We ended up taking a regular cab from our WDW resort (CBR) to our Universal resort (RPR) and it was $28 including tip. I think that's around what Uber quoted us anyhow. There were cabs available waiting at the resort, so no wait time involved either.