I don't think those values hold any meaning, specially after no concrete details are actually listed. For example, if hypothetical spot instances have a lower unit cost but your system needs to be over provisioned to account for systematic cold starts and cluster chatter, does it make any sense to say they are cheaper?
> This information is wrong.
Is it? Forward your complains to Google, then.
https://cloud.google.com/compute/docs/instances/committed-us...