He was once or twice in Sakura's gift for really cheap, but that was before it got nerfed. Currently the cheapest event he is in is treasure of the sage 120 cps/frag. Imo he is a good ninja if you get his bond mystery and if you don't have any other carry. If you can't get his bond mystery he is pretty bad.

P.S. You don't need to save 20k for a ninja. You can collect fragments slowly over time. Just decide what ninja you want in the long run and start buying fragments whenever you see them in good events. If you are f2p best events to get fragments would be lucky board and missions mobilization, they are not necessarily the cheapest, but you get power items too for your coupons.

Since root only covers 3 ninja, I'd say it is a meh team and very rng dependent.