I know you've asked about Dublin to Orlando, but last year we got a great deal on a charter flight flying from Belfast. At the time the tour operators (mytravel.com) were able to sell us a week car / flight / hotel for £179 (insurance for car was extra), in mid April. So cost wise, it might be worth your while checking out.
It was a direct flight, which may help if you are travelling with children, service was good, and it was into Sanford. The parking while we were gone was cheaper than the equivalent stay at Dublin, and there is a hotel in the grounds of the airport if you wanted to stay before flying out.