Wild growfruit trees have finally started appearing & maturing in my game. Those can be worth a lot, when perfect. Also, they seem to ripen in my pockets. I keep them around for a while, and sell them in bunches. The fruit objects also seem to be worth a lot as well. However, masterpiece paintings can be worth up to $14,000. Sometimes, the small ones can be worth over $10,000 as well, and they don't take as long to paint.