MMO's are different from regular online games in that thousands of players are able to log in and play together on the same server in a persistent world. Meaning things can change even when you are offline.
So naturally the costs for servers will be high. This is why there is a subscription. Some devs like to charge for micro-transactions in order to give players the core game for free, and if you want to buy certain things with real world money, like weapons, that option is available to you.
Thanks for responding, but what do you do in the game? is it just quests you do?
“Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying.” Arthur C. Clarke