On the basis of that, ROI will depends on the network usage. The more deals(txs) will going through network, the more roi(fee) you will get. With the increasing popularity of sonm network ROI would be a huge. However, it's clear that this won't happen overnight.
The buying of enough SONM for a master node is some kind of risk now. It will worth the buying if SONM will succeed in the future, while if it is not popular the investment will be in a loss.
Highly doubt it will be a loss, this company aint going anywhere. Read between the lines, do some research on fog computing then rethink that statement. Good thing about MN's is you are still the holder of the tokens...so it being a loss would mean snm price will only go down from here...again not happening. This is not another shitcoin, real world use cases keep popping up with the tech.. moon is an understatement. Mark my words
You have it all wrong my friend. The masternode will give a better reward, its like buying an appartment to rent out or renting out a room for air bnb. The team in no way takes you hostage. Either way do whatever you feel is the right choice.