I've been running chinese helmets for years, because branded helmets are simply insultingly expensive. There's no good reason why a piece of moulded foam should cost 300 eur. Just like there's no reason why a bike jersey should cost 100 eur, let alone 200.
One caveat: Specialized came out with a road helmet with a carbon fiber shell. It's not just a piece of foam. The chinese version is just foam, which makes it dangerous. But pretty much all the other road helmets i know of are just moulded foam, and foam is foam. By that, i dont mean that a chinese helmet is just as safe, but for the riding i do, i'll take the chance.
One thing that chinese helmets dont do is MIPS. Then again, until MIPS was a thing, people were riding just fine without it, and so, i ride a helmet without MIPS.
Another caveat: if you race / race crits, then maybe buy a real one, to have the peace of mind? If you commute, the same?