We have one model for cheaper construction of nuclear, using exactly the same designs as in the US (AP1000) or EU (EPR), and that example is China.

I don't think China is building them any less safe. I don't think the regulations are significantly different.

I don't think any of the designers of the nuclear reactors want to build them any less safely, either, because they are not asking for that.

Many of the "safety" stuff is also about prolonging longevity of the reactor as long as possible. Like really inspecting the welds on tubing, etc. Any reduction in safety there also ultimately increases costs by reducing the lifetime of the plant or heavily increasing maintenance costs.

That's why I don't think this is a tradeoff between safety and cost. I think it's a tradeoff between construction/design competence and cost.