Sorry for answering in English.
Я по-русски понимаю, но не могу всё писать по-русски если тема такая сложная. Извините пожалуйста!
I want to explain some principles about running international trains in Europe. Basically there are three ways to organize international trains in Europe nowadays:
classical cooperation trains
Still most trains are operated in cooperation between the state railways. A train Vienna - Munich is operated by OeBB in Austria and by DB in Germany, despite the fact, that OeBB rolling stock is used for the whole train.
Each carrier pays for the costs (locomotive, stafff, infrastructure charge, energy charge, etc) in it's own country. For using OeBB rolling stock inside Germany DB pays a rental fee per waggon-km (and/or locomotive-km) to OeBB.
Ticket incomes are shared. OeBB gets the ticket income for the Austrian section, DB gets the ticket income for German section.
There are other routes, where German rolling stock operateds in Austria, in this case OeBB pays a rental fee to DB per train-km. But the train operating company (also responsible for train driver etc) is always changing at the border station.
In the past, also the direct RZD waggons were operated on this base. The were attached to other trains, and if one bought a ticket Moscow - Vienna, the income was divided amongst RZD, BC, PKP, CD and OeBB according to the prices for each section. The sleeping car supplement went totally to the owner of the sleeping car (RZD in that case). Depending in the individual agreement RZD also received a compensation per waggon-km from foreign railways.
Also trains like Moscow-Berlin were classical cooperation trains, where RZD usually provided waggons (and thus received rental fees per waggon-km), but train operating costs and tariff income were shared.
Problems start when one railway company finds out, that it's part of an international train isn't profitable anymore (ticket income share lower than operating costs).
This didn't affect only trains from Russia to Europe, but also trains within Europe. One possibility is cancelling the train. But often the other train operating companies wanted to keep the train, because it was profitable for them....
"commercial train":
That's when the "Unternehmenszug"-concept ("commercial train concept") emerged: Since many years OeBB operates night trains to Germany on it's own risk. DB is still the train operating company (TOC), but OeBB compensates DB for all costs they have, and also gets all ticket income also for the German section (as they are considered "carrier" on the whole train route).
Similar concepts exist with some Austrian trains to Italy.
This concept is also applied for most Russian international trains nowadays.
The cost per train-km includes infrastructure usage fee (depending in the country; about 1 EUR/trainkm in Czech Republic, 1,5-3 EUR/trainkm in Austria, 3-10 EUR/trainkm in Germany), the traction unit (locomotive), the traction energy, the train driver, the train staff (conductors), parking trainset at the point of destination, maybe service charges (e.g. filling water, emptying vacuum toilets), etc.
A carrier (like RZD) can organize such a train in cooperation with state railway companies like OeBB or DB, but can also engage private train operating companies as partner, as they might offer better conditions....
Regarding costs for a "commercial train" in Germany OeBB has some advantages over RZD, as OeBB can use own locomotives and own train conductors (but also own assets cause costs) and doesn't always need to include also these costs into a "commercial train"-contract with DB.
own train operating company
The third concept is still not very common. It means that a railway company works as train operating company in different countries and operates the international trains really by itself with own ressources and without a contract to a local train operating company.
It might be cheaper than the commercial train concept, but only if many such trains are operated, because then you neeed ressources (locomotives, staff, etc) in every country where you want to operate. That's still difficult for European companies (different rules and languages everywhere), and impossible for a company from outside the EU (however, RZD might set-up a local company somewhere in Europe, but I doubt that that makes sense for RZD).
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I think that the third scenario isn't an option for RZD, but they might look for better conditions for operating commercial trains (maybe with other private partners and not the typical state train operating companies).
The infrastructure charges are the same for a train with RZD waggons, but they are only a small part of the whole train operating costs in a commercial train contract. Getting a good price per train-km often needs hard arguing and a lot of knowledge about the actual costs...
Some European train operating companies are known for charging quite high prices for "commercial trains", which might exceed the actual costs substantially...
In some cases they might search for ways to operate direct waggons in the classical cooperation way (instead of running whole trains). Possibilities for that are limited, because suitable trains to attach waggons are needed and the operators of that trains have to agree on that.
But in general it's not only RZD which has to deal with this questions. Competition has forced also European Railways to focus more on profitability, which caused cancellation of trains and new operating concepts ("commercial trains").
Sorry again for the long posting in English. Maybe someone can translate it to Russian.
Все равно сможете ответить по-русски, я в принципе всё понимаю, но писать для меня труднее чем ситать...