Once you make something a commercial project, you have to pay people wages to do the work. So say it takes 6 weeks to set up a MU* if you're working on it full time with two other people (since I'd say it takes roughly 3-6 months calendar time, if you're volunteering your time & earning your money elsewhere). The average outsource studio charges $75-100 an hour, which is roughly analogous to hiring a skill person in California on payroll, plus then you have to throw in another $75-100/hr to manage them. Let's assume in this case your outsource studio is full-service and you, as the project owner, will do the management (which is a rookie mistake). So, $75-100 an hour for 6 weeks for 3 people, which is 720 hours of work, which means you're looking at $54-72k just for development of the content & custom code.

Then you add on server costs, marketing, promotions, user-acquisition, testing, and you're looking at $100k just to get to launch day.

This is where fandom really consistently undervalues itself. I make roughly $60 an hour *salary* plus bonus, vacation, healthcare, etc to do less work than I did running a MU* (because my job here is management + production, not management, production, community management, user acquisition, content development, and coding).