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?
Depends on where you live. Also, if you’re importing from another country, you may have to pay import duties and tariffs, not to mention shipping. This may end up costing more than the domestic price for said item.