Matt, I certainly don't claim to understand all of this financing. That said, as I do understand it, your numbers relate to the total amount that all of those sales taxes generate, not the amount that the Vikings Stadium will use.
This is from the MinnPost article you linked to. It shows how much all of these taxes generated in 2010, as the city was still stumbling out of the recession. We would expect that these numbers have already increased markedly, as new hotels and restaurants have opened downtown. But for these purposes, let's assume that they don't grow at all, not even due to inflation. The lodging and hospitality taxes generate $34.1m per year.
The article notes that the city is on the hook for $675m over thirty years, when all interest costs and operating support are factored in. That works out to $22.5m per year, much less than the $34.1m that the hospitality taxes generate.
Some articles note that the city could be on the hook for up to $890m over that same time period, but that "worst case" only occurs if the city's haul from the above taxes increases well-beyond the growth projected in the legislation. My personal opinion is that this likely
will occur, but while the city is chipping in more towards the operating costs, it also will be keeping a much higher portion of the hospitality taxes to go towards the general fund. If you note, $890m per year over 30 years is still less than the $34.1m that the hospitality taxes generated in 2010.
Not factored into all of this are the costs of the Convention Center and Target Center. But note that the overruns on Target Center are currently being funded out of the general fund, so being able to pay for them with a portion of the hospitality taxes is a real plus for taxpayers. And the big convention center debt will be paid off by 2020.