Personally I would suggest slowly collecting Playboy Sasuke. While Refines, Coins, and such bring you BP, Playboy Sasuke unlike Konan is never gonna come out of a card flip. when you see him, use your points to start working on him. If you don't spend any money it make take 4-5 events to collect him but in the end he is worth it as he is EXTREMELY powerful because he is a "p2w" ninja. Refines, Coins and such c*l be obtained easily other ways.

Ok so just saw in another post the PB Sasuke is going away for quite some time so apparently those of us who were collecting him are screwed.