Originally Posted by
aaupgrade
Detailed invoice won't matter.
Correct, Costa Rica departure tax is not included in the price of any tickets for flights departing Costa Rica. You can pay for the departure tax at many major hotels for a fee, which means you can avoid departure tax the line at the airport. The cost is slightly higher but worth it IMO. I tend to do this the day before departure so I don't have to rush and/or worry about delays when checking out. However, it sounds like you may not be at a major hotel since there is no phone where you are. If that's the case then get to he airport a bit earlier than normal. It's $29 and must be paid before checking in for your flight.
Not true anymore, we was just there (in and out of LIR) in February, having bought tickets towards the end of last year. Both my girlfriend and I on American, and the other two couples on Delta, had the departure tax included in our tickets. Perhaps American was still working things out on the back end when the OP bought his tickets in June.
However, after seeing the line to pay the departure tax at the airport I certainly agree that if the OP has to pay the tax himself, he should do it before heading to the airport.