Russian Railways has introduced a special offer for travel on train #19/20 between Moscow and Rostov-on-Don. A ticket for an upper berth in a compartment costs 2,199 rubles, while a lower berth costs 3,711 rubles, according to Travel.ru.
Tickets are on sale until August 31st, and travel is possible from September 10th to October 31st. The promotion can also be used for shorter routes on this route. In this case, tickets should be purchased for the full Moscow-Rostov route and used only for that portion.
Source: travel.ru