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)

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.