Sounds like the fair tax by Neil Bortz.

High sales tax on all “new” products. None on used. A check to everyone each month so that poor don’t suffer from it.

Basically eliminates the IRS, and much of the Tax compliance / avoidance industry. Stops a lot of the tax nonsense that corporations and congress loves.

The problem with that is, people (usually rich people) will stop buying expensive stuff in the country, and they start buying them from another country that does not have any sales tax. Rich people avoid taxes and poor people are now stuck with the VAT on their daily needs.

Or, as a government professor I once had said, "You can only eat so much filet mignon a day."

Variants of that are even older. Here's one variant of a quote often attributed to Adolphus Busch: “You can only drink 30 or 40 glasses of beer a day, no matter how rich you are.”

Tax purchases made overseas.

Tariffs are already used a lot.

Yeah more or less credit it back as a function of income by way of monthly payouts. At a certain income the credits begin getting phased out slowly. You can also tax different things at different rates. For instance, vegetables sound be taxed differently than yachts. It also lets externalities be taxed the entire lifecycle of the good or service.