Google's sharing capabilities are lacking, so you will need to make a copy before you can modify the quantity. Just check back for newer versions as it is updated. If you would like to contribute, and knowledgeable with Google scripts, let me know and I'll provide edit permission.
https://docs.google.com/spreadsheet/ccc?key=0Agfu67LVN53NdHdmOVVaX2lhLWQyblBuaF9FYjk2SVE&usp=sharing
Notes..
- CoinBase isn't working yet, I can't get their API to work yet.
- BitMe won't format in dollars, working on it..
- The script uses price only from JSON sources, it does not factor in quantity available (yet)
- Sometimes the ON EDIT triggers do not copy over, if the exchange prices do re-appear when you delete them, do this..
- Tools/Script Editor
- Resources/Current Project Triggers
- Click here to add one now
- Select options updateExchangeRate,From Spreadsheet,On Edit
- Save, close and delete another BTC Price (Cells B4, B10, B14 or B19). These cells show appear immediately.