China would be able to produce 1,000 warheads in no time if needed
Exceptionally good chance China currently has well over 1000 active warheads already.
Let's summarise the learnings and facts.
1990s western
ESTIMATES on number of Chinese warheads based on what Chinese government claims is around 300. Context of this era is CCP taking extremely low profile for rapid development base. Even if they had 30,000 warheads by miracle, they would say something like 300 or "Britain and France levels". And being + or in between is inconsequential since 300 or 600 really is still a low count in comparison to Russia and US.
30 years later the same estimate is being used to claim China has 300 warheads by a wide variety of folks with some very different interests and agendas. Better to cut the shit and ignore all that motivated posturing talk.
China has an economy that is still supremely undervalued with a currency that is undervalued. Yet it is already nominally the size of the US economy which is trillions in debt kept afloat only from their financial hegemony. It is also hyperinflated by FIRE sector. Whatever though let's just say China is about US size and is on the up and up with only realising about 20% of its full potential now and already steaming upwards to catch the US while the US is rolling downwards. Momentum and inertia matter but I would say this at least means China can afford to match US warhead numbers. That's just a fact.
Next, China has a population size over four times that of the US and slightly more than the US combined with Russia combined with Europe. That's a lot of people to protect with a properly decent deterrence or at least a lot of people to avenge with global coverage in case it is struck first. More reason to have at least equal warhead count to US. It should be more since US warheads would realistically be focused on only the nation it is performing strike on whereas China would need to have enough warheads to cover every city in US and Europe + whichever other antagonist. This depends on policy but it is fair to assume this is the ideal capability.
So tldr China has both the funds and the moral obligation to ensure its citizens that it has at least as many warheads as the US. Consider also how often threatened it is by US since the Korean war. MacArthur wanted to nuke China same with many hawks after. This hasn't changed since the 1960s. So there are the funds, the obligations, and the necessity.
How could it be that modern China still would feel secure with a measly 300 warheads? It shouldn't surprise anyone to learn they've stockpiled over 3000.