China as a monopsony buyer of Russian gas will be able to set the price, even one that does not recoup the capital costs.
Even before the invasion, the Power of Siberia had been viewed as extremely unprofitable (it seems likely that corruption played a major role in driving up costs), and then there's the further issue that more work is necessary for it to send its total capacity, which is a fraction of what it sends to Europe.
> Yet the project does not appear to be as grand a success as Moscow would have liked it to be. To begin with, the capacity of gas production on the Russian side of the border is open to doubt. The Chayanda gas field in Yakutia region, currently the only source of gas for the pipeline, can produce up to 25 bcm a year.
> To deliver 38 bcm to China, Gazprom has to develop another large field, Kovykta in the Irkutsk region some 800km south of Chayanda, and connect it to the Power of Siberia with another pipeline, which has not been built yet. The completion of the infrastructure needed for pumping the required volume to China is probably going to take more than 10 years, according to Gazprom’s pre-feasibility study of the project.
> ...
> Currently Gazprom sends westwards about 200 bcm annually via a number of pipeline routes. The Power of Siberia project, however, has a limit of 38 bcm and it is unlikely that another major pipeline project would be launched any time soon. Thus, the Russian company would not be able to switch export flows as it pleases.