Ultima Online cost only 5-6 million

There's two factors pulling against each other.

The processors and toolsets have gotten much more powerful, and much cheaper; someone can now whip up a game in a couple of days in Flash that would have taken Nasir Gabelli a couple of months in 6502, and he was a genius level programmer. In Unity, you can download a few assets, whip up some terrain, and have an avatar walking around a map in a couple of hours. It used to take ages of puttering around with Win32 calls just to get something on the screen.

The flip side, of course, is that consumer's graphical expectations are now much higher.

If Portalarium had gone for an original UO isometric view, with relatively low level of detail, the game would probably be done by now.

 

That's not an issue with the Unity engine per se.

Totally agreed. I realize that organizing enough to make use of the talents of the community members would require a ton of overhead, but it would eventually pay dividends.