In my example, I clearly explained the cost with tax was $130.
In addition, your continued use of tex-exclusive figures isn't accurate either, since the correct t-e figure is 29.87%, not "30".
Actually, the correct figure is 29.87012987012987012987012987........but I think most sane people would accept 30% as a round figure for 29.87%.
Well, no, Rongie. You clearly stated something quite different. You sopecified the "cost" was $100 which (as is called out in the bill) would include the sales tax (tax inclusive, you see).
And as for the "correct" figure, 29.87% would be the normal statistical rounding to two places and NOT 30.00%. That's merely more dishonesty. Use 29.87% and I have no complaints; use 30% and it's obvious you're trying to fool people.
I think most sane people would accept 30% as a round figure for 29.87%.
Why would any sane person allow a business to round a tax rate up and end up paying more than is due?