So, you want to make a MMO?
Can you afford your own decent server? Can you afford to maintain it all by yourself or at least hire someone to do so? Can you afford to still provide content and stuff while dealing with marketing, technical support etc.?
MMO means Massive Multiplayer Online, massive meaning a lot of players. That alone has a large inherent cost that you have to be prepared to overcome for at least several months before the balance breaks even. That is if players actually stick around and not jump the ship for another brand new MMO.
Loyal players stick to their favorite MMOs, since they're time consuming, they just can't afford to play more MMOs. Other players, they play MMOs until they get bored and move on.
What am I saying? The MMO market is overly saturated already, new MMOs are being released weekly and we all only have so many hours a day to play.
You are better off doing small scale stuff like Minecraft (which is definitely NOT a MMO), it is low cost and more likely to yield profit. Once you've got such small projects down under your belt and have some financial backing as well as experience, you can start thinking about larger projects.
*falls off the soap box*