Most of the One Piece games are boring, so it's going to be a waste of money either way. If a Sucker Punch developed One Piece game ever came out, then that would be a different story.
Pirate Warriors 2 is pretty good but you should enjoy the Dynasty Warriors games, because it's the same concept. You can even get pre skip characters with different moves. Idk if PW1 attacks are the same as pre-skip PW2 but it's fun using pre-skip Luffy in PW2 and using his gear second special because it ends with him being Chibi Luffy. I've just started playing Unlimited World Red but it's not gotten great reviews, I'll be able to give more insight on it once I progress some in it.