I have pointed my own miners to CEX.IO to mine scrypt coins and have been happy with the results so far. I was going to use some of my profits to buy some of their GHS, as it sounds attractive having cloud based miners. I am having some difficulty trying to figure out the profitability part though, and hope someone can enlighten me.

According to the profit calculator on their site, if I buy say 10 GHS at current rates it will cost me approximately 0.11488 BTC for those 10 GHS. Going to the 'Estimate Profit" calculator I enter in my theoretical 10 GHS and leave the other settings at default I get a cumulative profit of only 0.05 BTC before it stops returning anymore. This is not even 1/2 of what it would cost me to purchase the hash-rate.

I cannot believe people are buying hash at twice the expected return, so I assume I need to change from the default values in the calculator to make proper projections. I further assume the maintenance fee and pool fee cannot be changed from 3% each? If so, please let me know. This would then leave the values for current difficulty (again I assume this is from the block chain), difficulty increase per month (default 50), conversion rate and conversion increase per month. If someone can help give me the appropriate values to base my estimates on I would be extremely thankful.