Getting there by train
If you can make some more time available, consider exploring Russia by train. After three or four days on bord of the Trans-Siberian Railway you get the feeling of the enormousness of Russia. It will make you comprehend the many problems of Russia far better than when travelling by plane. Not to mention what you can actually explore on the journey: your first contacts with hearty Russians and slowly but surely you will loose your sense of time...
When journeying from Europe you won't get this feeling as much, because there are too many stops and border controls in between and the wagons are not as cosy. Besides, the acquisition of the visas of a transit visa for the Republic of Belarus is annoying and expensive.
Our recommendation: per Flight to Moscow and then take the Transsib!