For now only coin drain is Equipment & group, later Chakra system gonna be the new coin drain in town,
but it's prob not coming here, until a few months.

I would say Seal Treasure is not worth it, since you can get most of those ninjas in the shops, with the different coins, better save for Tendo(50) or Sage Treasure(60), if Sage Treasure is even on this verison. :P

Well in the old days maybe, since it's changed at CN, since I got Madara Treasure at 65 :P
& Sage at 60.