That anime scale figurine costs $300 but when accounting for the sales tax: it’s closer to $340. However, you discover a listing on Mercari that prices the same for ¥20,000 ($124) in brand new condition without imposed sales tax as the seller resides outside US jurisdiction. By using proxies as an intermediary for importation and shipping costs: does that alone elude sales tax?
Laws will vary widely from state to state, but in most (many? some?) US states, the “sales tax” is more accurately titled “sales and use tax.”
You may be asked on your year-end tax return to list anything purchased out of state that was brought into your state for use, and to pay the appropriate tax on that.
In my state, it’s on the honor system. So almost entirely unenforceable, especially for small items. Look up the laws in your area, though.
To sum up: technically, probably not; practically, probably so. This is not tax advice.
This is the most accurate answer. If you really wanted to, you can probably get a refund from the other state for the sales tax paid, but it only makes sense for very large purchases.