Meals (in Sevastopol Branch of MSU) average 800 RUB (per day). If you plan to buy rubles in Russia, you should take US dollars or Euros to exchange. Please change money only at banks, hotels and airport exchange bureau. It is an offence to change money from street traders!
Current exchange rates of the Russian Ruble (RUB) can be found at the Bank of Russia webpage http://cbr.ru/eng/daily.aspx