We are referring to static ROI looking at the difficulty change possibilities. Since we cannot predict the change in difficulty level we are mentioning only the ROI as per present day condition.
Then you should consider either removing the word "static" or completely changing the sentence in question... In its current state, it's quite misleading!
Also long term plans can easily achieve 200-300% ROI.
A 1080 days BTC mining plan at $89.99 can easily achieve static roi based on present day profitability of 264%.
Would you mind providing a detailed breakdown of the costs, in order for us to easily understand how you're capable of achieving such profitabilities?
Every th/s sold will enable us to purchase more hashing power in terms of new miners. That will help us generate new income. Also, hosting our miners in place like Georgia where we have access to electricity at $0.05/kwh onwards help us keep the operational cost lower.