Trans-Mongolian - Step 1: Buying the Ticket

I bought my ticket to Mongolia today - a one-way ticket from Moscow to Ulan Bator.  I will fly back to Moscow from there.  The only place to buy tickets for the Trans-Siberian and Trans-Mongolian railways is the international ticketing window at Yaroslavsky Railway Station in Moscow - one of 9 main stations in Moscow and the rail gateway to the Far East.  The cost of an "SV" ticket (2-berth compartment) is 26,638.36 rubles (about $451).  Not bad for 5 nights (96 hours and 55 minutes) and about 6,266 km.  Departure to be on Train #006Ш at 23.55 on Wednesday 22 March 2017.