We booked BWI/MBJ with AirTran. It was by far the best priced flight we could find and it was r/t direct. Go to their website and use the flexible date option and you can find the most reasonable price for your trip.
You may also want to do the same on Kayak just in case another carrier would be offering a better rate.
Nice to see you posting again Smith. Hope you do another "on location" trip report.
Timm