Hahaha nice 
But... G-black is 2099$. Hashrate is 25Mh/s, so it's 83,96$/mhs... not really a good affair, in comparison the Zeus Thunder X3 is @ 1999$ for 28 Mh/s, so 71,39$/mhs...
But your G-blades prices are nice, 399$ for 5,6 Mh/s (you're the cheaper seller on the interwebz, GG
), it's 71,25$/mhs, better go with them 
But... G-black is 2099$. Hashrate is 25Mh/s, so it's 83,96$/mhs... not really a good affair, in comparison the Zeus Thunder X3 is @ 1999$ for 28 Mh/s, so 71,39$/mhs...
But your G-blades prices are nice, 399$ for 5,6 Mh/s (you're the cheaper seller on the interwebz, GG
), it's 71,25$/mhs, better go with them I agree with of your calculations above... but you are forgetting that the G-Black is fully self-contained with a PSU and controller, while the G-blades and Zeus are not.
Also the Zeus chips use nearly twice the power of the Gridseed chip... G-blades clocked at 838Mhz use 90W with a stable hash-rate of 5.6Mh/s... if you have access to free or cheap power than this is not important... but since I pay $.22 per KwH... the extra power consumptions removed any savings of the Zeus chips over the GSD chips.
So impressed with your analysis~ I think I should just watch you guys kicking this topic around, cuz I am totally lost in thoes numbers.