We traveled to AC from Tulum recently, just up the highway from Playa. Take the bus if you want to save LOTS of money!! From Tulum it was just six dollars U.S. apiece to Chetumal. From there you can hop on another bus to Corozal, that was only about $3 for both of us!! A taxi will set you back $25-$30 U.S. plus tip. The bus waits for you as you pass customs and immigration. Once in Corozal, grab a taxi to the airstrip to Tropic Air, they will fly you to SP for $35pp one way, many flights throughout the day. You can take a bus to Belize City and take a ferry to AC, but the flight is very quick, scenic, and well worth the money. Have a Great Trip!!!!!!!!!!!!!!!