Not OP but yes if you consume more jam (not if you consume the same over a period of time, because you're then just paying less for jam over a wider time scale).

The example I've heard given is accounting and spreadsheets. It made accountancy cheaper, but people then started asking more questions and analysis became a thing.

Rather than just taking the reduced spend as profit, companies wound up increasing their accountancy spend overall.

Well consuming more jam per unit time would still be supply and demand, you have to spend more on jam overall because you can buy a cheaper jar.