We need to know other things before we can evaluate his cost.

Theorycrafting section:

For example at tree lvl 1 you have a chance to get 2 coins, lets assume all prizes have equal % of pulling (which obviously wont be the case later on). You have 25% chance to pull 2 coins, so every pull you get 0.5coins. At this level, you'd need to spend 800 coupons to get 20 points, thus 1 frag. Now lets look at tree level 7 and assume same unrealistic scenario that u have equal chance of pulling each item: 12.5% chance for 6, 7, 8, 10 coins, so 8 draws will get you 31 coins, so 3.875 coins on average. With that assumption you can get 20 coins for 103,22 coupons, reducing price 8 times (still, expensive for his age and what this ninja is worth). Now the price might be slightly lower, because we are not living in a dream that tendo/9tails naruto will have the same rate as filler rewards, thus increasing the overall rate for coins. Can't say, he might get cheaper, but im 100% sure not to the point, where that gigantic investment into leveling tree will be returned.

* * *

We have no idea how many points we need to upgrade the tree- if personal tree is related to global in a way, that you can level your own tree once global gets higher lvl, then high lvl rewards are literally unobtainable. If it isn't corelated, we don't know how many points are needed to upgrade each level (level 1->2 requires 20, whats next?) and with every draw used on lower levels you have lower income than taken into account in calculations above.

Sidenote: if you arent sleeping on money, dont go into rng events like this. They *.

Then wait for other events.

@Sharinganbattousai hidan requires you to spend 16k ingots somewhere during this week.

He hasnt been in treasure of the sages during 6 months, no idea if he was there before that. Last time I saw him in 9tails strength where he was ~90 cp/frag if i remember correctly- and that was the best deal (still meh) we had in a long time considering getting his frags. Unfortunately during my playtime he was always featured in ingot requiring events or in rng/bad value events like this one.