Worth asking at the airport if you can pay to get in. MGA has a lounge operated by MGA airport, some airlines you get in free (COPA for one) in J, others you don't but you can pay $35 and get in that way with better services than the free admit. Also there is heavy sponsorship with credit card issuers and thus discounts even though paying depending on the card used. Cannot hurt to ask or consult their web site.
In the case of MGA it is almost worth it to go through the most relaxed security check imaginable (don't bother taking out the metal objects, we'll just use the wand) plus on departure if you are too lazy to go to check-in they do that for you and check your bags too.