It could be worth it if it was funded properly (long post).
For example, let’s say the Rooney’s privately funded everything except a retractable roof. Using
@Sean Miller Fan ’s estimates and accounting for inflation, a ballpark number may be $175m in 2030.
One of the biggest arguments against tax payer-subsidized stadiums (and why I’m typically against such proposals) is the unseen economic activity theory, or the idea that the money not spent at a sporting event (assuming the team relocated) would be spent elsewhere in the area since the majority of fans in attendance are local residents and not out-of-towners. Evidence of this (though not without its flaws) is comparing the GDPs of cities such as St. Louis and San Diego before and after their NFL teams left.
Events such as the Super Bowl or the Final Four wouldn’t necessarily follow this theory because the majority of its attendants are tourists and the money generated from it wouldn’t be made up for under normal circumstances. If a Super Bowl in Pittsburgh generates $80m (the average of Matheson’s two numbers) and a Final Four in Pittsburgh generates around 50-75% of that number, those two events alone would generate $120-140m that wouldn’t otherwise flow into Pittsburgh’s economy.
If it could attract a few other events throughout the stadium’s lifespan that would only come if there was a roof, an argument could be made that a publicly-subsidized retractable roof could generate enough to offset the initial cost.