Union dues?

I'm curious whether there's a notable difference in labor costs in Chicago v. Indianapolis. I'd guess that there is just from cost-of-living considerations. I don't know if these kinds of workers would tend to Unionized in one locale but not in another. But even so, I can't see that accounting for five times the cost.

Another thought is whether being trapped in a city with parkland surrounding it makes it a more expensive demo and cleanup with various EPA compliance that might not apply to a city block surrounded by parking lots.

There also may be more effort to build around the stadium, as they seem to want to keep the Soldier Field colonnade and incorporate that into the park. I'd guess those costs weren't part of Lucas Oil considerations. For instance, SoFi in LA cost $5.5 billion. I imagine that also included costs to incorporate the stadium into parkland. But they also probably spent a bunch of money on architectural design. The initial proposal for the Bears has more flare than Lucas Oil (which isn't to say it's any more attractive). They seem to lean into the space ship theme instead of a simple, symmetrical dome.

But still, that's eye-popping.