[Manuel_D]

Not coincidentally, that study only decided on 1976 for its analysis. If I order 6 plants of the same design, then drop the next batch down to 4 plants for the next run, then 2 plants for the third run, then I should expect the cost to go up as scale goes down.

Here's a publication that points this out. In fact, it calls out the article you linked specifically: https://www.sciencedirect.com/science/article/pii/S030142151...

See that cluster in the late 60s and early 70s: https://ars.els-cdn.com/content/image/1-s2.0-S03014215163001...

That's the benefits of scale. The slower pace of construction after that is accompanied by higher costs.