If you know someone in IT, it’s worth asking them what their company does with old computers. At my last place, we sent off old PCs to recyclers, old often only being 3 years or so. Most of them were basic i5s with 16GB of RAM, but they were more than powerful enough for a good docker host. I’ve got small stack of them that I rescued from the recycle pile.

Not to mention the laptops that went to the recyclers. Of course, many of you might think that is wasteful, but the recyclers were refurbishing them and reselling. We got them off our hands for free, and they got to make a few bucks off them.