Here's a CLI as well which is specific for coinbase. In addition to viewing rates it will also let you buy/sell/transfer and more. https://github.com/rdegges/btc/
Maybe it's not my place to say but the tabbing made the code hard for me to read. I'm learning Ruby and have always been told to use 2 spaces. Are tabs ok too?
Sorry about that. The way I setup Sublime Text, the tabs don't appear to be very large but when I push to github, its way too big. I made some changes that should make it better to read.
Its been a long time since I wrote Ruby code, but if I recall correctly I believe the community is overwhelmingly in favour of 2 spaces as opposed to tabs.
Looks great. One feature that would be appealing to me is real-time price updates when the change and in indication of whether the price increased or decreased.