Over the years, a lot of devices have accumulated at my home.
I'm currently thinking about use-cases for them.
Some of them are too beefy to just collecting dust, so I probably will sell them. Others are so old that probably no one will use them, even for free, like a laptop from 2007.
So I searched around on the interweb and found a nice post about reusing old hardware.
The old laptop uses ~0.015kWh, so this comes down to 40€/year of power costs (365 * 24 * 0.015kWh * 0.3€/kWh).
My raspberry pi uses ~0.003kWh, so this comes down to 8€/year. A new raspberry costs ~80€, so the savings of 32€/year in power would be amortized after 2.5 years.
Money-wise it seems to be more reasonable to buy a (used) raspberry pi and use it for a long time. But it would create more waste and more consumerism.