In April Reuters reported that China approved ten plants for $27B (total):
https://www.reuters.com/sustainability/boards-policy-regulat...
Whether they run over budget (or whether this is an under inflated figure) is yet to be seen, but it would seem that China is bringing the cost down, and substantially.
I'm not a nuclear expert by any means, but from the reading I've done, they're largely designing and building the reactors themselves these days. And it seems that to help keep the cost low (among other reasons), they're also helping other countries build them.
Yes, China have a good shot at doing it because they are building 33 simultaneously now and they have questionable workers rights and environmental policies.
As I said, if a developed country can do half what they’re doing (ie twice the price and double the construction time) in the next 20 years it would be a miracle.
It's not really a fair comparison though, is it? Is a questionable environmental policy worse than a bad electric grid? America has a dirty grid that has fairly limited capacity. How many fossil fuels will we burn (producing electricity, and powering non-EVs) because we aren't building nuclear? The environmental benefits of having nuclear power probably largely make up the difference (if they don't exceed it), and that's over the time scale of a century or more where we'll need to catch up.
Workers rights I have no real knowledge on. But China isn't known for their track record on any kind of rights, and arguably US blue collar workers have a pretty awful quality of life that the government largely doesn't take the blame for (because we don't have state-run healthcare and minimum wage doesn't keep up with the cost of living). China has forced labor, America has legalized slavery in the prison system. Plenty of American industries rely on the unethical use of migrant labor while the state disappears those same people to "alligator alcatraz" or overseas prisons. I don't know the full extent of how bad things are in China for the kinds of workers who build these plants but I am hesitant to overlook how bad things are in the US.