That's the problem, too -- it applies equally to necessities and luxuries. Sales taxes are regressive because there is a certain amount of non-discretionary spending everyone has to make, regardless of income, just to live.
Clearly the numbers should be adjusted if someone wants to turn this into a serious tax proposal, but it seems possible to design a progressive sales tax.
Yachts were more expensive and due to highly elastic demand, the industry plummeted. Companies went under or laid off thousands.
But don't worry. Guess who works at yacht manufacturing plants? Not rich people. They weren't hurt, and they were fine with taking their money elsewhere.
However, if I misunderstood and you advocate having the same tax rate on luxury goods as other goods, then we are in agreement on this point.