Installing a network throttler.  Just a browser takes up 2GB a day.
Limiting speeds to 2Mbps will also not stop me from racking up 2GB a day.  Browsers find a way to sneak things in. We'll have to see if it worked.

This was the first lead. Simple script, use existing system tools. However some tools are not available anymore
https://github.com/TheTomorrowLab

this is a solution that I could implement.

http://blog.greggant.com/posts/2018/01/30/network-throlling-macos-osx.html

Chrome has profiles on the network tab in developer tools.