The price you quoted for an MMO to start up from scratch has me a little worried since the forerunner of the" spiritual successors", City of Titans, is running on less that one million dollars based on what we know about their finances
Most of that is labor, keep in mind. Sometimes hundreds of employees, costing from high-5 to low-6 figures, over 5-8 years, the price adds up. Average, say, $80,000/year, 100 staff, 5 years == $40 million. CoT has almost all volunteer labor (we have used three contractors for specialized tasks), reducing this cost dramatically. I calculated out once that if we had been running a typical MMO studio, with the salaries expected, based on hours of labor invested by all of our volunteers, CoT would have, as of last November, run $16 million.
Consider the cost for a movie for a moment. Remove the payroll, and you can easily produce what looks like a Hollywood blockbuster for a token amount. And people have done just that (Safety not Guaranteed, Monsters, Moon, Primer, etc). Many of these cinematic shoestring masterpieces use deferred payments, with the cast and crew being paid out of the profits from the movie's release. In CoT's case, the volunteers are also the company's owners, so we get our "payout" from the game's release. I cannot tell you how any of the other projects are handling this, because I honestly don't know and even if I did it would be impolite to do so.
This is partially why MOBA's became so big for awhile, they take less time to develop. Less time == lower labor costs == lower budgets == sooner they can recoup the investment. Cutting the labor cost from 5 years to two years goes a long way to reigning in production costs.