Ballpark property tax at $12K * 25K = $300M/yr
Ballpark state sales tax at 4% of $50K in spending * 25K = $50M/yr
Naturally, some of the property tax is displacing existing property tax payers and some of the income tax will be lost to other employers moving out of NYC area, but it seem quite reasonable to be OoM $500M per year at scale.
For one thing, they won’t all be engineers. Cost of living is also lower than SV.
It only takes a minute or two verify that $250K is a completely unrealistic estimate for the average salary of a likely HQ2 employee. In fact the state's own estimate is around $150k. The property tax estimate is similarly skewed -- on top of the fact that you're ignoring the additional cost of services to support all these people.
I'm not saying there's benefit-to-cost ratio argument to be made in favor of HQ2 (if everything were to boil down to those terms) -- just that you seem to be, well... pulling numbers out of the air.
NYC is big enough to have a healthy relationship with Amazon, and part of that is knowing is that you’re the seller, not the buyer.
The point is that the gain in revenue from income and property is being presented as basically just "free" money. It's not.
The usual costs per new resident (that property taxes are normally earmarked for) perhaps?