Booking of Russian trains tickets is possible via official
RZD website, there you won't pay any additional commissions and have 100% guarantee that everything is legit. The only problem is that RZD still didn't manage to create English version interface for booking, that is why in order to succeed with handling Russian version potential passengers will need a sort of guide (or at least some rudimentary knowledge of Russian language). We sent you a sort of guide (in pdf format) on email you've entered when registering on forum. If you have any further questions (like regarding details of purchasing process), we'll be glad to help