Best nation in central america. They're basically lower first world.
Not entirely. They have seen large increases in there standard of living in the past 10-15 years as well as rising real wages but they are still not up to first world standards. They are more like Uruguay and the richer parts of Brasil than a first world nation though if they continue to de-regulate their economy and continue to grow the high tech industrial base that they have cultivated in the last 15 years they could be on their way.
And again it is the best nation in Central America mostly because of the overall sh**ttiness of the competition. With the exception of Belize and possibly Panama Central America is an economic basket case.
Why making an exception for Belize of all countries? It is, actually, poorer than Panama, even with the PPP (purchasing power parity) adjustment (and much poorer if you don't do that), not particularly different from its neighbours such as, say El Salvador or the Dominica Republic. It also has a huge crime problem in its only city worth the name.
Actually, unless you do the PPP adjustment, in "raw dollars" Panama is per capita wealthier than Costa Rica. It is only with the adjustment that the ranking reverses. By the way, PPP GDP per capita in Costa Rica is not above that in Mexico - the CIA page puts both at $10,000, still just around a half of that in, say, South Korea.
The real reason Costa Rica is different from its neighbors is that it is relatively egalitarian, so there is somewhat less deep poverty (though there is still quite a bit). Furthermore, it is somewhat more orderly, so things function and function less chaotically than in some of the neighbors, resulting in a much better impressions for a visitor. It also didn't have civil wars, coups, or other major conflicts in a long, long time. Nearly all of its neighbors have suffered from these things repeatedly, so the comparison of stable Costa Rica with until recently war-torn countries is not entirely fair.