most economical is Viator.com to get to and from Negril.....Roundtrip is $34.99......they use Holiday Services...
Holiday Services is fine but what you pay is what you get.....you gotta wait till they fill da bus and drop off lots of travelers usually
just contact Holiday Services after booking online (or before) and tell dem where the pickup and dropoff locations are.......

Cool Runnings, Marko