http://mining.thegenesisblock.com/a/6dd76c6ce6Mine looks good. The biggest problem with your calculation is you used BTC for price of hardware. 90 BTC.
Just want to know where you got 90 from? Because in-order to have paid 90 BTC, the exchange price would've had to been at $70. It hasn't been at $70 for quite some time now so... dumb or just starting shit?

Oh wait you're that idiot who canceled their order because you're bad at maths and now you're in here now just to troll/spread fud because you're butthurt.