The Russian MOD budget is around 120bn USD give or take, about the same as the Bundeswehr's. The Russian MODs production capacity surpasses that of the West and their puppets in the east combined as is being demonstrated, because the Russian MIC is configured to defend Russia's interests, not to make profit for the elites and not to appease stock holders. They have many factories that just sit there on stand by for when needed, courtesy of the USSR.
Russia gets a lot more bang for the buck with their equipment. The Ruble is undervalued versus the Dollar or the Euro. In Russia salaries are lower. Energy prices are lower, and a lot of the raw materials have lower price as well, because they are locally produced. Like you said most of the military industries are owned by the state and this also means profits are not as much of a concern as with the private military industry in the West.
A Su-35 costs 2 billion RUB ($22 million USD at the current exchange rate). And an F-15EX costs $138 million USD.
Even the Su-57 costs 2.236 billion RUB. Which is a mere $24.4 million USD at the current exchange rate.
This price difference does not just apply to fighters. You see the same thing with nuclear submarines, frigates, corvettes, and other weapon systems. Advanced Russian weapon systems cost like a fifth the price to produce.
I would not be surprised if for "dumb" weapons with less imported materials the price difference was even higher.