I have mixed feelings because there’s no way to tell if a cash discount is legit. They can pad an estimate to win no matter what.
Take my wedding reception for example. Proprietor said you pay cash no tax. I said that’s 8.25%, but you save 40% income tax so let’s split it 20% discount for cash.
He said no. So I said then I’ll use Amex. It was like $12,000, so was I foolish? I don’t think so at least I earned 3% cash rewards. Also this forced the establishment to declare income so I think he was foolish not to counter. If he said 15% I would have accepted.
With hvac, there is no tax in PA, so that’s why no monkey business with a cash price. My .02