People already own gridseed units and are currently mining with them at these power consumption levels.
I was under the impression this is only being done with non-scrypt coins.
Currently running 32 gridseeds, total power usage is 270 Watt. 10 Mh/s works fine.
There you go -- there's an owner of them. 32 gridseeds would run about US$6-7K, right?
I paid around that, the current average for such a set would be 6000 USD.
They're annoying to keep running since it's "a new product" and not much has been invented/cristalized though.