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.