Where to buy fresh, not overpriced fruits and vegetables? Not in a supermarket and Not at one of this fancy indoors markets. Instead, find one of "Weekend Markets" - ярмарка выходного дня.
Quality is mainly very good, definitely a way better than of the "plastic" fruits in chain supermarkets. And prices are about half of what they are at Dorogomilovsky, Danilovsky and Usachyovsky.
Ярмарка looks like the white color tents for 12-70 stalls. They operate from Friday to Sunday. There are about 50 locations throughout the city, and here are several most central ones. Check, maybe one of these addresses are close to where you live.
metro Smolenskaya (line 4 not 3) - 2nd Nikoloschipovsky, near the metro
metro Ulitsa 1905 Goda - behind the metro
metro Frunzenskaya - near the metro
metro Prospect Mira - next to Schepkina 47
metro Sukharevkskaya - next to Pankratyevsky, 5