We'd only consider supporting that once it is out of Beta. I don't want to be a position of exhausting valuable development time on a payment method that may completely change. Once it has reached a stable state will take a look at it for a future release.
It's not just a matter of cost. There's only so many hours in a day and I've other tasks with higher priority right now. I'm in the middle of working on CB Activity 6.0.0 so I can only afford time for minor implementations on other projects right now.
Have made a feature ticket for this in the meantime.
forge.joomlapolis.com/issues/8832