How wealthy the inhabitants of Vrndavana were simply by raising cows. All the cowherd men belonged to the vaisya community, and their business was to protect the cows and cultivate crops. By their dress and ornaments, and by their behavior, it appears that although they were in a small village, they still were rich in material possessions. They possessed such an abundance of various kinds of milk products that they were throwing butter lavishly on each other's bodies without restriction. Their wealth was in milk, yogurt, clarified butter and many other milk products, and by trading their agricultural products, they were rich in various kinds of jewelry, ornaments and costly garments. Not only did they possess all these things, but they could give them away in charity lavishly.

From Srila Prabhupada's Krsna Book chapter 5: The Meeting of Nanda and Vasudeva