$26 per day according to TC, for a full Mini (6 core i7/32 GB RAM). If you do enough that you can get high utilization that is cheaper than the CI services. (e.g. travis wants close to double for 2 vCore/8GB VMs) EDIT: On the other hand, renting a physical machine at Macstadium is a lot cheaper, so you'll want to have the AWS integration or some flexibility...