Rodrigo has been making scripts for OCI for a while now. Yesterday he again added some great work to his collection. A super script to retrieve all your consumption / billing data from OCI and save it to JSON files, so you can easily process it in excel or any kind of analytics software.
His latest post explains in detail how the retrieval of all this data works and he shows some really nice examples of charts made with this data. The chart making process is not detailed yet, but Rodrigo says he will follow up with that. So keep an eye out for his blog!