Well you have to understand the economics of Korean gamers. They have cyber cafe's all over the place. They have more gamers per square mile compared to Free to Play gamers in the USA. They collect more income through population, that they won't really need to put a high price on things. USA in the other hand has to cover a wider region to support a stronger server. The game is still free to play, but they would need to collect income some how. If the players doesn't 'pay' much, then the server won't do as well.
This is just a theory, but I've finished my Micro- and Macro-Economics to understand how business goes.
I'm not trying to get people to pay more here, but people shouldn't expect much from Free to Play games. At least they given us a chance than not giving us a chance to collect permanent items (with Pesos) at all.