Have you considered buying a used thin client / mini PC?
Since the Orange Pi 5 sounded interesting, I checked it out and it’s rather expensive. Well at least for me.
I found it from 180 to 200 Euro for the 8GB version. An used thin client or mini PC can be bought for half the price and most of the time it comes with 256gb storage included.
The extra cost for energy should be less than what you might be paying extra for the Orange Pi plus storage.