$10/GB is high. Purposely high, because the point of Google Fi is to use WiFi as much as possible and avoid cellular. So it's there if you need it but you don't want to need it much.
This hardly works for the connection which is actually providing your WiFi, or if you want to try to use cellular exclusively.
This hardly works for the connection which is actually providing your WiFi, or if you want to try to use cellular exclusively.