But Tom... what would Russia spend the money on? Lets say they have unlimited money. Or slave labor. Whatever. They can spend any amount of money. Where would they shop? The weapons Ukraine is getting is more advanced that most of what Russia has thrown into the war, which means Russia hasn't kept up, militarily. (Your note about the spending is probably why) As such, they can't buy what they need nor make it. They've been cut off from most of the world and the arms markets. MAYBE they can buy from China but China seems like they want to remain mostly neutral-Russia. Helping them a bit and being friendly, but not jumping into the war with them.
Also: While china is an economic powerhouse, not sure Brazil is anywhere there.
Also also:
China is condemning the actions likely because they know it'll make Russia happy AND not matter.
This is a similar thing Politicians in the US do. When a bill that they, personally, approve of but their voters hate it, they will vote against it if its almost certain to win.
Its easy to condemn anything, so long as it won't happen.
The situation is that China is buying from Russia, not the other way around:
https://www.aljazeera.com/news/2022/3/9/infographic-which-countries-buy-the-most-russian-weapons"Russia is the world’s second-largest arms exporter: India buys one-quarter of those weapons followed by China, Algeria, Egypt and Vietnam."
Russia doesn't really need anyone to sell them weapons. They have the plans to make decently performing tanks and planes and rifles and whatever they need. There are plenty of Russian and international companies willing to take Russian money and build those tanks and planes. In a major war Russia can also just tell its companies to convert their factories and make equipment for them, for which they will pay for.
China's role is to primarily to sell Russia electronic components and raw materials for its weapons:
https://www.wsj.com/articles/chinese-firms-are-selling-russia-goods-its-military-needs-to-keep-fighting-in-ukraine-11657877403"BEIJING—Chinese exports to Russia of microchips and other electronic components and raw materials, some with military applications, have increased since Moscow’s invasion of Ukraine, complicating efforts by the U.S. and Western allies to isolate the country’s economy and cripple its military."
If you compare the size of Russia's defense industry to the US it might seem that Russia's defense industry is still rather small, despite being the second-largest arms exporter, but this is mainly because it is direct USD to USD comparison and does not account for the fact that $100 USD is worth a lot more in Russia than in the US. The US is also encumbered in that it has to maintain hundreds of US Military bases around the world, and provide foreign protection to its allies, whereas Russia is not as encumbered. Almost universally, such graphs and comparisons do not account for this inequality and attempt to show the US as the biggest and best in terms of USD spent.