Although nice that the cute old little couple found an agreement after all of that passionate chaos they caused in between one another, trying to protect each other. Let's get back to the Wheat Grain project King Michael specifically asked for Mogranius' assistance on.
Why would King Michael bother working with something so cheap to increase profit you might ask. Simple, it's cheap! 50 kilograms of Wheat Grain costing around 20 Gold Coins here in Ignis at average, can equal to a total amount of 100 Gold Coins(50 Kilograms) worth of flour coming out as a result. When the hired Farmers convert Wheat Grain into Flour so it can be baked into bread or various other foods with it, half of the fish intake would be cut down in Gaster Kingdom! This is fairly an economic game changer, because Fish isn't cheap and can be used to set up another stream of income.
