Just imagine Income Tax + Sales Tax... get taxed on what you earn, then taxed again when you go to spend it!

This is a clever way to reduce purchasing power without making it seem as bad, ie. nobody really considers the tax on a new car purchase until they're signing the final paperwork... or even on a new T-Shirt. Depending where yo live, this sales tax is non-trivial too, sometimes up to 10%+.

Sales tax is the most visible tax. Maybe the richest of rich people do not consider it, but I have a hard time believing "nobody" considers it.

Do you add up in your head how much that fast food meal will actually cost before you order it? How about when you try on new shoes? Probably not...

Yes, it is trivial to add 10% (or 30% for waited restaurants) to a number. Even if people did not for small purchases, with so many people living paycheck to paycheck, surely they notice an extra $50 to $150 for a TV or $3,000 for a car.

One of Amazon and other online only retailers’ biggest advantages until 2018 was that it did not have to charge sales tax to people in states without a physical Amazon presence. That meant you saved 7% or more buying from Amazon instead of locally. Basically everyone I know used to buy online to skirt sales tax.

https://en.wikipedia.org/wiki/South_Dakota_v._Wayfair,_Inc.

It was a very big deal and politicians had been complaining about waning sales tax revenues.

If the tax is on the gains it's still a single whammy.