buy low, sell high
Business is simple: buy fruit from the sellers, and sell it at the market. Unfortunately for you, the economy has a mind of its own. At their own whimsy, the Banana Farmer, Grape Farmer, and the Market House declare and end sales, or increase and decrease demand. You'll have to be fast if you want to keep your sales up!
Each Salesman is given a single button with an identifying color. In order to buy fruit, they must find their color socket among the grapevines or banana leaves; in order to sell it, they must find the appropriate socket at the market stall to sell each type of fruit. Buying and selling is directly correlated to how fast you can ship by tapping your button.