cross-posted from: https://feddit.org/post/23170671
I need to keep power usage in mind and don’t want to spend more than 500€ on hardware. Power is roughly 0.35ct/kwh in Germany
I like the small square machines (former NUC). But I don’t have any overview which ones are worth the price.
For data storage I am thinking about a NAS, but it would need at least two HDDs for redundancy, otherwise it’s not better than an external HDD that I have. Also it does have its own power draw, which isn’t insignificant (10w->~300€/10years).
Capabilities of the machine don’t matter too much, I will see what I can do with the hardware I get.
Is there a sweet spot, a device that everyone buys or cheapest brand or best package or whatever?

Your own calculation is the thing that should pick the machine. At 0.35 EUR/kWh a single watt running around the clock costs roughly 3 EUR a year, so the gap between a 25 W old laptop and an 8 W mini PC is about 50 EUR a year, or 260 EUR over five years. Half your hardware budget, paid in electricity.
That’s also why cheap used enterprise gear tends to be a trap at German prices: low purchase price, 40 W at idle. An N100 or N150 box with 16 GB and an NVMe drive sits around 6 to 10 W idle and fits inside 500 EUR comfortably. On the storage side, two 3.5" disks add something like 8 to 12 W if they never spin down, so spindown is worth configuring when access is bursty, and if your data fits on SSDs the power question mostly goes away.
Thank you you’re right I agree.