Keep hoping OC - its going to be easier, I think its eight days from Vladivostok to Moscow, and therefore more time to St Petersburg, which is worth seeing. A major part of the cost is food etc (like a ships cruise). In about 5 years you will be able to do Beijing to Moscow in about three days on the the high speed line that Russia and China have agreed to build (Now in planning stage).
So consider, In year1, start from St Petersburg and travel to Moscow, seeing the sights in both places. Save up again and when ready do Moscow>Beijing>Vladivostok., though you can do Moscow>Vladivostok.
You can also (now) go from many European cities through Kazakhstan to Beijing or Shanghai. And, it will get simpler and cheaper as the Chinese implement their plans for rail connections to Europe.
Btw, the line in my post is not the trans-siberian, if anyone thought it was. It's this one: http://www.nordrail.com/tour_travel_yamal_arctic_railway.html