I guess they will sell the chip with respect to the nominal speed of 100 GH/s for $13. But at this operation point you will not have 0.06 J/GH.
Yeah my interpretation is its more of a headline efficiency which could be used in the second half of this gen (like S4/S4+).
Anyway, this would still be a good price.
$0.13/GH certainly isn't terrible when you consider how cheap their reference design is to make and should allow the OEMs to get by at least for now.
Have you got information regarding the reference design or are you just guessing?