Savings: unknown (held in cryptocurrency, private)

Tax: divide by zero error

Besides, doesn't the US already have sales taxes? Or are they state-only? I'm starting to favor a tax on real estate and/or land value, since that's physically impossible to hide.

State. City. County. Sub-divisions of same that are special sales tax districts and have extra sales tax applied. Not every instance of those entities applies a sales tax, but any could and many do. Basically everything except federal. The sales tax where I am, in a "red" state, is about 11% (we actually have a really high effective all-inclusive tax rate in this state, for how entirely shitty government services and infrastructure are)

> I'm starting to favor a tax on real estate and/or land value, since that's physically impossible to hide.

The challenge with that is the system for assigning value—everything else about it is easy. We already have something close to what you'd need in the US because real estate property taxes are common. That system's not perfect but it may still be good-enough, despite its flaws. It seems to work kinda OK. That might change if that became a more important revenue source, and for more levels of government, though.