Looks interesting lol

It really depends on the nation. Most generic countries will have a considerable amount of PP by the time they've formed an empire, but some nations with longer focus trees and decisions will still be spending all of their PP on more important things. I found that I couldn't justify spending 250PP until about 2283 when playing TOC. Ultimately it is personal preference, and I prefer it to be a bit cheaper so I don't have to wait for cleaner borders.

250PP is absolutely nothing in the late game. Should be between 500-2000