You will either need a van or two
taxis for four of you plus luggage. The standard taxis are usually Nissan Sentras and not that big for four people plus luggage.
A van should cost you $520 pesos
equivalent to $43.50 US if you pay in pesos.
If you pay in USD they will charge you $52.00. The airport
taxis exchange at 10 pesos to the dollar and not the 12 pesos to the dollar which is about the going rate right now. There is a money exchange and an ATM at the airport if you want to change dollars to pesos or get pesos from your ATM account.
Have you checked the cost through this website? People that have used this website for private transportation have been very pleased with the service.