Atm hes mostly available in the events like spending (balloons) or konoha's great tree, in which the price varies on the ammount of cp/gold spent. Last time he was available in a semi-good event, it was nine tails strength (which hasnt been there for last months), in which his price was around 80-100cp frag. In comparison, konoha great tree while low spending has prices inflated to such an extent, that you overpay about 2-3 times, about 200++ per frag.

Personally what I'm doing is as long as he won't show up in a normal event, I wouldn't spend cp on him, just get the free redeemables and slowly piece him up for free. When his price goes back to original 80~100/frag, I'll consider buying the rest.