I recall Musk stating that a fly back to the cape is very fuel heavy and the sea barge is the way to go for the foreseeable future unless the payload is very small. By the time of 1st stage separation they are over 220km downrange with ~4.5 mach worth of velocity. This would have to be eliminated, the stage turned around, fly back to the cape and have enough fuel to land. Very high fuel penalty even though its not a 1:1 ratio of payload to fuel on the first stage.
Biting the hand that feeds IT
