New concept: “Spot” VMs on cloud services <https://www.theregister.co.uk/2020/05/13/azure_spot_vms/>. These are offered for a very low price, but equally the jobs run at very low priority, and are liable to be evicted at short notice--as little as 30 seconds, according to the article. They are there to fill up unused capacity that cannot be sold at the regular rate. But as soon as a customer appears willing to pay that rate, out you go.