It's true that Jevon's paradox doesn't always apply, although this does seem like a classic case.

But yes, if sold for a negative margin Jevon eventually stops because the decreasing supply will drive up prices.

> things are made that will sell for less than the cost of construction

Price is set at the marginal cost. Capital costs aren't in marginal costs.

You'll need a better counter-example than UK railways which suffered from Parliament price-fixing.