So for Moscow so far the best I have found until now is NXVOICE, they charge USD 59 for set up plus USD 13 each month plus 0,0377 for incoming minute see link
http://nxvoice.com/pricing.html or if you dont need own number there SIP service called SIPNET.RU they have local call in-numbers in every major city in russia. Unfortunately their web pages are in Russian only