I don't know how the situation in Moscow is, but i can tell you what my experience was.
in August 2004 I had an accident in Mogoja, on the 'zilow gap', and there were only those old babushkas working at the train station. The meaning of their lifes is to make your life hard. I wanted to send my bike to vladivostok, 2000kms further east
generally spoken, there are two possibilities to send your bike by train: Either with the post-wagon (postochni-bagashni-wagon or something like that), or you have to rent your own little container.
The babushkas didn't like my motorbike. Friends of mine sent their bikes with the post-wagon from chitta to vladivostok, so this is still possible. But they have a weight limit, which is around 200kgs. Although i tried to lie, they didn't believe me, and I couldn't make them believing (money or so.) And my friend told me that in chitta they didn't make any problems with the weight.
So, I had only the alternative to rent a container, which was more expensive. And much slower. For the 2000kms it took about two weeks.
With the post-wagon you pay by kilo, the other by kilometers and renting the container... I think it was about 100 USD, but i don't remember exactly.
Let me know if you need any more information.