I asked the question on SJO a few days ago, and their ansewer was as follows:
As TACA, we do not have a VIP Lounge in San Jose due to airport regulations. You would have to wait for your flight in the regular waiting lounges. However, the airport has recently allowed the opening of one VIP lounge that is run by a travel agency. Their fee is 25USD. Their facilities are more than adequate.
What do you think about it?