Did your calculation include fees?
No I didn't take fees into account 
I am in the process of assembling an economical mining rig at a cost of approx. $725 with an output of 1125 or more Mhash.
What hardware? I view it as a hobby as much as anything.
A hobby? But there's not much to do once it's all set up. I think what I am going to do is wait for the 7000 series cards to come out then reassess the situation.