I don't think it is likely cost effective to farm(if it were enough people would be doing it and estates would not be inflating in price).
The most cost effective way of doing it is waiting for the bonus days and then going for it with all you can.
Even so these tend to not always yield 1 licence pet eon, though it is closer.
Ultimately the best combo is likely to start a number of campaigns and get to just before the battles which have rewards. Then when your bonus day comes along, you start with all of these battles so that you maximise the time you have on that day. |