Sofia is a typical village. The stores themselves are poorly stocked and would never suffice to feed the village. To get an item you need, or feel you can sell for a profitable price, the barter system is used extensively. The barter system also works with medicine, shoes, clothes and almost every other good. It is really the only way they can make money.
Money is needed to pay for electricity and coal or gas and other needs and wants.
The cities are different. Most people live in high rise apartments and thus have no land to raise crops on, resulting in a more desperate situation. The system of buying food from farmers might actually work fine, but it is not steady and is very unorganized. Some people manage to make enough money at their normal jobs to survive. The city people get paid every once in a while, not enough to live on for most, but the villagers almost never get paid.