When you leave Margarita, there is an airport tax that varies; it is around ten thousand bs. When you leave Caracas for the US, the airport tax is around US$90 = 200 BSF. This is not included in your ticket no matter what your travel agent may tell you so keep some cash on hand. Some flights allow two suitcases weighing seventy pounds each to Caracas but then the connecting flight to Margarita may only allow fifty pounds each for two suitcases.
From Caracas it can be cheaper if you buy the ticket at the airport rather than booking direct. The flight costs about $60 and and there are 3 airlines [Aserca Airlines, Aeropostal, Conviasa] that make the trip to Margarita everyday. If booking to (PMV) comes back higher than expected, try inputting (CSS) as your destination. Although if you are arriving on a Friday, a Venezuelan long weekend, Christmas, Easter, Carnival or during August it is very important to have a pre-booked ticket.

Other Airports in Venezuela also fly to Margarita Island such as BLA : Barcelona with Avior Airlines, CUM : Cumana with Avior Airlines, MUN : Maturin with Conviasa Aero, PZO : Puerto Ordaz with Conviasa Aero and VLN Valencia with Aeropostal.