IMO no. i bought 1. but i play multiplayer 99.9995% of the time.

I would say maybe. I never play multiplayer anything and have no idea whether or not that interests you. For me I was enjoying the DLC up to the point where it gets to COM level 3 and especially level 4. For me it just gets too difficult and it's in part because the game deals the best cards to the COM. I'm not the only one who's experienced this as you can find some threads in the Discussions dating back years talking about it.

On the other hand, up to that point it was fun. Hana-Awase is interesting because you have to remember some different Yaku.