Interesting thing about 9 tails chakra price: it may seem like you're better off trying to uncover tailed beasts one by one. It's a trap, on average (you may get lucky and spend only 80-90 coupons for the rewards) the price to get all tailed beasts is 730-740 coupons (depends if you still have free try).

edit: Of course that's assuming each tile has an equal chance of having tailed beast inside, which we can't be sure about...