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?
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.