At a deep discount. The buyer would run the risk of secondary sanctions by the U.S. They would also, likely, want to take custody, all of which can result in striking discounts. (I beliece Iran got dimes on the dollar for their gold.)
https://www.bloombergquint.com/global-economics/chinese-stat...
It’s almost explicitly Western policy at this point that Russia would be better a Chinese vassal than regional power. If Putin winds up dependent on Beijing, that isn’t great, but it’s better than the current situation.
Historically China is a quasi enemy of Russia.
Russia was plotting to nuke China in 1969 over their border conflict. They have rarely liked eachother and are not traditional allies.
https://en.wikipedia.org/wiki/Sino-Soviet_border_conflict
https://www.scmp.com/article/714064/nixon-intervention-saved...