Departure tax is 800pesos or £45 sterling per person - cash only, paid at the airport, as you queue at check-in.  

Departure taxes can vary depending on a multitude of factors- plan for it to be high . Authorities tend to be inflexible on the departure tax, so make sure that you are prepared!

Departure tax are now mostly included in your airfare, you can print the receipt of the air ticket just to be sure.