Hi!

I recommend spending on what works best for you, but always remember to stack it. So for example, if you are not only spending coupons but also ingots. Then make sure whatever you are spending towards, will always have some sort of rebate or return besides what you are looking for. One very good example of this is Lucky Board where you get not only prizes from rolling the dice, but also redeemable rewards from the points you earn (This works best when there are ninjas you want to recruit). Remember to always stack above the discounts and you wont go wrong =>

Hope that helps!

~Jib