The only way he could collect NC sales tax from you is if you travel to NC and physically receive it from him in that state. He cannot collect sales tax on an item sold and delivered out of state. Oh yeah, if NC is like most other states, he must be in a business licensed to collect sales tax to do so. Arizona has NO agreements with any other state for reciprocal collection of sales taxes, and no sales tax on "casual sales," i.e., between private parties, within the state. I agree with the other posters, sounds like a deal best walked away from.