Years ago (1991) in Canada, there was a massive change to the sales tax structure. It was quite convoluted, where things like 1 donut incurred tax, but a dozen had no tax. Potatoes had no sales tax, but of course, GST was levied on car sales.

Several large car dealerships immediately advertised that they were no longer selling cars, but expensive potatoes. If you bought a $12,000 potato from them (no tax), they'd throw in a free car.

You can imagine how long the government put up with that.