I buy kitchen ingredients in the public market during weekends only and on weekdays the supermarket is my haunt for food items. Vegetables and meat are definitely cheaper than the supermarket. Take for example the 2 heads of broccoli that I got from the public market for 100 pesos (around $2), one such head will cost moer than 100 pesos in the supermarket. Even fish is way cheaper at around 80%. The advantages of buying in the public market aside from the cheaper prices is the freshness. And the downside? It is not air conditioned and there's no security guard.
We have a farmers market here in the summer, and the price are usually higher for tomatoes and other fruits and veggies that we get there than they are at the grocery store, but they DO have a wonderful flavor, and are local and fresh. The Farmers market is not that close to us, so we have not been there but once this whole summer, and one time when we thought it was open and it wasn't. There is a small shop that does sell local produce and it is right on the way to the fitness center, so we stopped in there the other day, looking for fresh tomatoes. They had beautiful tomatoes, from the Amish farms, but they were $3 per lb for regular ones and $3.50 for the Cherokee Purple ones. I got a couple, but that is about three times as much as they cost at the store. I think that if we go to the farmers market, they are only $2 a lb there, so at least cheaper, and still local farm-grown tomatoes. Today, we went to Kroger and they had the red and green pepper marked down for clearance, so I got a couple of bags of those, chopped them up and put them in the freezer for meals this fall and winter. I try to get the clearance veggies and fruit when they have it because it is a lot cheaper, and then I just have to get it prepped and some of it frozen so it does not spoil before we can use it.