Sales tax has nothing to do with mining.
Sales tax/use tax absolutely is important because it means getting 5% to 9% less equipment for the same price. Same with import tariff or VAT. There are strategies to defer sales tax for up to a year, but it needs to be paid eventually. That's why it's worth considering zero sales tax states like MT/NH/OR as long as the power is cheap enough. If you're selling hashrate to customers in the U.S., that can be considered a taxable service in some states like Texas, while other states like Pennsylvania don't tax it.
You are talking about a few separate things.
If you are running a business (that in theory is making money) in New York those items are tax exempt.
If you are buying them to run for people then depending on how you do your service it may or may not have taxes in NY
If you are buying them to run for yourself but selling the hash to others then it's taxable.
The above 3 lines can also be 100% wrong depending on how you setup your business and contracts and deal with other things.
This is why tax lawyers and accountants charge so much.
-Dave