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.