So i spent 25k coups on this and got 3 minato frags only, but the overall rewards would be valued at around 45k coups. Not too bad, i can finish minato in 1 month or less.
To be exact:
-125 danzo
- 80 shark
- +3k power
- ~450 cave keys
- 12 seal scrolls
- a lot of summoning scrolls, like 60 or so
Maybe the value of all of these things would be at 50k coups even :O