This is a very important question. Supermarkets are cheaper than
small family-owned shops, but the latter are more useful for the local communities. In a large shopping centre you can buy cheap food but usually it's not good quality. A lot of products at the supermarkets are not made in Poland, and your money is going abroad to other countries. On the other hand, you can get a lot of things in one shop,and you have wide choice of goods. Small shops are good for people who want to buy Polish food but it`s more expensive. The advantage is that in small shops you are sure that you get fresh food and most importantly that it`s Polish.
Here goes. I've made some stylistic changes to it if you don't mind :)