I had little too much time yesterday so I made a simple ROI calculation in excel. Anyone who wants to calculate earnings in staking and BRO investment feel free to check it out. Not perfect but it gives you an idea what to expect.

Its very easy, you just have to enter 5 variables and expected costs:
-Expected price of BRO in USD
-Number of Bergstake
-Staking days
-Invested BTC
-BTC price in USD

Download link: https://mega.co.nz/#!YVQVBJyQ!pHBjN37JH1OelgQcLlR1pgidpEW-U0ki1LNkBBrzVrc

If you think i should add something, let me know.

Hope that will come useful at least for someone.