[esskay]

A lot of it depends on what you use it for, in my usecase I've kept the two Pi's I mentioned as they sip a tiny amount of power. The Lenovo Thinkcentre I've got sits idle at around 7w but it's running a fair few service I use for dev work throughout the day, and the Pi would struggle to cope.

If you used one for something equivilent to a pihole then I think yes it would cost more over time, although we're likely talking many years of 24/7 runtime for it to then become more expensive, the low power x86 chips are a lot more efficient than they used to be.