"costed" is proper when referring to the past action of determining the price for something to purchase. "Last week Sheila costed out the parts list, so it should be accurate."

"priced" is proper for both the past actions of determining the price of something to purchase or something to sell.

"Last week Sheila priced out the parts list, so it should be accurate."

"Last week Sheila priced everything on the shelves."

english is not esperanto. it happens to be the native language for a significant part of the world population, and they have no obligation to accept its bastardization for the sake of inclusivity.

in every non-western country with its own language, those "some" would get rightfully ridiculed.

> bastardization

What is this universal, pure English you've been speaking? I must have missed the tablets on which it was written?

Non jokingly: There is no "bastardization" of a natural language. It is spoken how it is spoken and insisting otherwise is missing the point of language (I suggest it is "communication"). There is no King of English to sit and dictate the rules except for the common languages spoken.

If you want to really grok the concept, take some time to figure out what a "language" actually is. I'll give you a hint: your first 5 definitions have obvious failings.

I don't agree that contemporary usage defines the language. We have a canon of English literature reaching back centuries, and people use phrases from e.g. Shakespeare without eveen noticing they're doing it. I think it would be a shame if learning contemporary usage should fail to equip you to read Shakespeare.

Descriptivism is all very well; but it doesn't seem to allow for any usage to be actually incorrect.