Before it was cheaper – something like 35$, but then in April this year a plane crashed there and 5 French tourists died (the pilot left unharmed.). the prices doubled since then, as explained to me later on that month by a local Taxi driver, because of some new regulations that made the tour agencies and the airport and everyone involved pay insurance and stuff like that, making the operation a few bucks more expansive.
I think that in these things – as in Flying an old Cessna in a 3rd world country, it's better safe then sorry, so pay the extra $ if it sends them to flying school…
Mark