I have heard many differing opinions on how far to upgrade the Treasure Trove, whether Level 9 especially is worth it. In order to decide for myself, I created a workbook to calculate Profits, Return on Investment, cost to upgrade, etc., and I thought I would share it
You can access this here: Treasure Trove Calculator
You will need to either copy it to your google drive or download it as an Excel file to work with it.
Let me know what you think, if you find it helpful, if something doesn't work.