How come? Assuming that the number of lettuce heads cut per member of a team is 200 (which is not very high - team total 600 including one packer and two cutters) $10 per hour equals five cents per lettuce head.
If only labor were the only expense.I guess you didn't notice the expensive California land those cutters were walking on? Or the equipment need to plant, water and fertilize the lettuce. Or the equipment needed to refrigerate, store and ship it to say my local vegetable stand in Chicago. Unless you think these other things should be free, comrade?