STS has to get us users to spend our money to NPCs so the gold gets away from the game. Now people are just farming more and then trade it between each other. This will of course lead to an inflation.
Th problem is not the prices, the problem is than the amount of money are just growing in Pocket Legends. Things that could solve this is vanities/elixirs sold for gold, or any other things people actually wants.
I am surprised they haven't done anything to this problem yet. As you said, this will destroy the game experience for new players.
Bookmarks