The company I work at pays for tuition if they see it being helpful to the work you do. I have been in a masters program part time for computer science, and am now applying for tuition help from the company since I'm a developer and this directly helps me with my work. If I was offered a management position, and they required me to have an MBA, I would go and do it as long as they paid for it (which I would imagine they would).
So I guess what I'm trying to say is, if you're going to pay for it out of pocket and not have a plan to use it directly for a promotion or a well paying job, then its not worth it. If you have an opportunity to get promoted or land a well paying job which requires an MBA, then do it (even if its out of pocket).
The first couple years of my master's program I've been paying out of pocket because I know I will need it if I want to move up from developer to manager (or higher). I just started working at this company this year, and they offered me to apply for tuition help.