I found another 30gh miner with a raspberry pi included for short money. So I'm contemplating getting that & the rig would be total 90GH+/- running thru the Rasp pi, power consumption is my primary concern, so if I could connect it to a solar panel with dc to ac power inverter that covered the total power demand, then I might actually see some roi at some point because of little to no power costs.
Honestly - at that low of a hash, you won't see much of anything trickle in. Your best bet is to go the "lotto" route. I think the problem too is that other faster units will solve things before you do and then your unit will submit work that has already been solved. I could be wrong on this