all those maths are relying very much on IF statements.
do be honest with you 5000 BLOC right now is worth over 14 BTC unless you are well off you can't afford this masternode. To refund this based on https://masternodes.online/ you need 2551 days.

No need for fancy maths reality is Blocknet is for well established long term traders/investors in crypto who got to buy BTC < $1000 or ETH < $100 or you are very well off period

I wouldn't suggest blocknet has a first dip in the masternodes eco-system. I would look at Nodium or Rhenium, masternodes, they are at around 0.2 BTC entry there is a potential of $200/week just over a month to get ROI and are projects that have room to grow but again DYOR I personaly have one Nodium masternode and I am assessing exactly how much will end up in my bank account.

Based on the work of https://twitter.com/OmniAnalytics you can see where investments will be the safer for you.
cheers