You could strap together 3x ROCKPro64s (6 cores, 4GB, $80 each) to make a half decent docker swarm or kube, if you've got the right kind of parallelizable dev workload.
However, I'm not sure how it would perform compared to my somewhat obsolete AMD Athlon II X2 260, and other posts have convinced me the power savings wouldn't necessarily be significant enough to pay for it.
