I admire your honesty but doubt that most people in New York are honest. Just look at the crooks they routinely elect.
As for the question of WayneS, there really isn't a question of constitutionality here. If I consume a meal at a McDonald's on the New York Thruway, I pay New York taxes even if I'm from Delaware. Even if it is take-out. It doesn't matter because it is a ready-to-eat product subject to the jurisdiction in which it is sold. If, on the other hand, I drive over to Delaware from Pennsylvania and buy a car with the intention of garaging and licensing it in Pennsylvania, our Commonwealth can rightfully claim a use tax under the law. I may not like it, but that's the way it works. If I want to avoid it, I can either move to Delaware, which is perfectly legal, or register and license it under the name of a friend in Delaware, which is considered illegal tax evasion.
That's why, applying the same logic, I should be able to enter a minus amount on this line for internet sales of clothing shipped in from another state on which sales tax is charged.