system
A chat on subreddit /r/wallstreetbets
human
You do realize that vat is included in the price tag elsewhere and the customer pays it, right? 
  
 Adding tax at the counter in the US is because of differing state and local taxes.

gpt
Its the same in a lot of places that have different regional prices, final price displayed on the shelf/website no extra taxes to be computed. 
  
 Australia, Brazil, China, Germany and a lot of others adopt this system, continental Brazil is bigger then the continuous US (discarding Alaska/Hawaii) and has varying state tax as well, price still displayed as total on the shelf.