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?
The US had a de minimis exemption for import of goods under $800 until recently. You could buy up to $800 and not pay tax on it when it was imported. That was recently suspended, and so if you buy something internationally, customs should charge you tax on it as it enters the country. Technically, it’s not sales tax though.