Banal but important details

Our trip was roughly a "Classic Trans Mongolian" tour organised by Real Russia www.realrussia.co.uk/

The train journey from Moscow to Beijing cost around £1400. This included all the accomodation in Irkutsk (3 nights) and in Ulaan Baatar (3 nights) and the Ger camp in Mongolia. 

We organised flights to Moscow (try Easy Jet or BA) and our first night's accomodation in Moscow. The BA flight to Moscow arrives mid-afternoon; there is time to fly into Domodedovo and still take train from Yaroslavskaya station the same night. We stayed a day because we could - and also because the flight to Moscow was paid for with BA Air Miles and had to be on the Friday.

Visas were organised by Real Russia and for the Russian, Mongolian and Chinese visas the total cost was £264. They were very professional and as quick as they could manage. You can have it done quicker still if you pay more still. 

You might pay less and do it all yourself - but unless you live in London that's a false economy, even if you yourself can afford six more than an hour long lunch-break journeys to and from the various.

The accommodation in Beijing was relatively easy to source; my daughter Josie did the research in Lonely Planet and on the web, picking Qian Men Hostel as the best of the bunch. It cost about £72 for the three of us to rent that one room with three beds, for three nights.

Exchange, relative costs, tips:

The Russian rouble costs about 10p - that is, R10 = £1. FOREX is available literally EVERYWHERE in Moscow, every few hundred yards. Cashpoint machines likewise, generally in secure locked areas at the bank, are common enough.
Moscow is very costly - a beer will cost £6, a Latte £4-£5.  The chain restaurant "Moo Moo" (spelt My My and distinguished by a plastic moo cow outside) is very reasonable. The Metro is R2/ride - that is, about 20p.
Irkutsk was much cheaper.  Taxis were cheap, trams very cheap.
Russians do not smile - smiling on the Moscow Metro can be taken as evidence of mental ill-health!

The Mongolian Togrog trades at about 2500/£. Mongolian costs are cheaper than Russian. A good cooked breakfast with coffee will cost less than £8. A main evening meal, around £10-£15.
Mongolians are very cheerful and love children and babies!

Chinese Yuan trade at about 10/£ and Chinese costs are very low indeed.