A quick calculation:
10 Gridseed Kit, 3 MHs = $200 x 10 = $2000
3 MHs at auto switching pool get you, let's see, 0.0045 BTC per MHs, so 0.0135 BTC a day, so you are making $5.805 (at $420/BTC) a day. It will take the buyer about 344 days to break even.
I feel so sorry for those who got snookered.
With gridseed blade it would be 1 blade, 5.8MHs= $1600
.0045 = .0261 BTC/day * $450(current BTC price) = $11.745/day = 136 days ROI
Not bad considering what it used to be but once Titan is released it is game over.