How do you beat yojimbo in Final Fantasy x-2?

There is a valley in the Calm Lands just before you would enter the path to Mt. Gagazet. Go on the path under the bridge, and there's a cave entrance on the left side of the screen. Work your way through the cave, and you'll eventually get to Yojimbo's Fayth. He'll offer you his services as an Aeon for a certain price. Offer about 20000 less than he asks for. Repeat two more times to get the lowest price, and pay him the money.