There were plenty of markets and black markets in USSR. Most of the time the only reliable source of meat and poultry for ordinary citizen was a "Farmer's Market" (Колхозный Рынок).
Actually it appeared a little before 1991, in 1989. There was first Internet connection to Finland in Demos institute (their demos.su domain is still operational) and I can remember reading their Usenet posting about communist coup d'etat in 1991.