OH NO keeping track of sales tax!. Amazon can keep track of the prices and arbitrary price changes in thousands of products but is flummoxed on keeping track of sales tax. Let's say 1200 is an uninflated figure (Ha!) and there's 100 city and country sales taxes, That's 1300 entries on a one time basis. I, myself, have done that. It takes one moderately fast person a few days.
Sales taxes don't change every day, they change AT MOST once a year. Most don't change for many years. keepng track of this would be negligible for amazon.
If it can't hack this, it shouldn't be in the internet business.
Lastly, Amazon has to have a physical presence somewhere in the US. It's warehouses must be somewhere and it's not even paying sales tax there. This is not about logisitics which Amazon has solved and more about not wanting to collect sales tax because it benefits their business model.