I know that taxes on booze or cigarettes exist when you buy them from abroad bringing that into the US (literally, not via mail) as they won’t let you enter the border without paying the tariff (despite only have 1) but its different if one is packing those in bulk quantities for reselling. This is not the same as sales tax since it affects tourists visiting and citizens returning for importing “duty free” goods or products.
Will I have to pay any additional tariffs for bringing in a foreign consumer electronics (i.e. a game console) via luggage (not mail) even if I have proof of purchase (receipt) listing the price in its original currency (no local ST)? It’s like if I purchased a digital-only PS5 (brand new, unopened) for ¥50,000 ($316) from a Japan trip while the same is $600 (before tax) if bought in the US, are there really any tariffs or not?
You will likely have to pay tariffs if you declare more than $800 worth of goods at customs, as you are required to by law. You declare them based on what you spent to purchase them, not what equivalent goods would cost in the US. Of course, you might also be the kind of person who bought their ps5 in the United States and then took it with them on vacation to do some light gaming in the hotel and is just bringing it back with them at the end of their trip; I couldn’t possibly say.