Several states have no sales tax, I'm sure you can find which ones by googling.
Just a word of warning, trying to import products into your country without paying the required Duty on them is illegal, and bad things could happen to you if you get caught.
Oh, its not that bad. You'll just have to pay the duty - and even then they are very lenient.
Years ago I was working and living in Singapore. Just before I did a home visit to Australia, I bought a new PC for my father. As it was two big boxes (CPU and the monitor) I was sent to the "red lane."
They asked me about the PC and I said I'd bought in Singapore but had been using it for over a year (which means no import duties levied). They looked at the box and said "it doesn't look old - it looks in good condition." To which I replied, well its just the box. I mean you take it out the box once only, then I just boxed it up again for this trip home.
They were thinking about that when one of the supervisors came over - she had been watching what was going on. Straight away she told them to open the monitor box. I didn't know what they would find but I could tell from the approach that they knew something I didn't.
Sure enough, they took the monitor out, she flipped it around and looked straight at a little plate on the back of it. Amongst other details was a date which was only a month or two ago (I can't remember now).
They read out the date and then looked at me. Without even hesitating I replied "well you know I was having trouble with the monitor and took it in for repair. They must have given me a new one."
They didn't buy it. They simply calculated the duty applicable, and then asked me to pay about 2/3 of it. And off I went.