Besides produce that they grow, they purchase fruits and vegetables from non Amish farmers.
Yesterday, I bought 6 ears of corn, 4 green peppers, a quart of tomatoes & peaches and 2 bags of yellow beans. This Amish family grew everything except the peaches. All of this for $9.25. I don't think a grocery store would beat that.
They also sell bread, jams, honey and pies that they make. I will not purchase any food items that our local Amish make. There is very poor sanitary conditions in their homes. In the fall they will sell pumpkins, squash, Indian corn and gourds. I love stopping at the stands in the fall.