I think you have to look at what you want to get out of it as well. From most accounts running a language centre is A LOT of work.
For me, to put in that much cash, time and effort I would want a sizeable return and a good chance to gain a source of passive income in the future. In other words that means getting a centre up and running and eventually stepping away and letting others handle the day-to-day stuff. But from the centre owners that I have talked with, that rarely (if ever) seems to happen. They seem to be forever connected with the running of the centre, if they are not there hands on most of the time, things quickly go to pot. That's a big turn off for me.
Your needs / requirements might be different however. For example, I could certainly see that for someone slaving away at a language centre, working long hours and earning 20-30K, the idea of running their own centre, being their own boss and improving their income could be quite attractive.