I'd have bet it means "buy" (like köpa), "cheap" is "billig" in german, even in low german. So my interpretation is "a port to buy at" (Kaufhafen, not a real word).
købe (danish) <=> köpen/kopen (low german) <=> kofen (vernacular german) <=> kaufen (german)
Do you have a link I could follow for your interpretation? Thank you.
Are you suggesting that my interpretation is different from yours? It is not. We are saying the same thing -- namely, that the English "Copenhagen" comes from Low German.
I did not say that the English "Copenhagen" comes from "billig" the German/Low German for "cheap". I said only that the English word Copenhagen and the English word "cheap" are related.
On that point, see https://en.wiktionary.org/wiki/cheap#Etymology
For a fuller discussion of the meaning of "Copenhagen", see https://en.wikipedia.org/wiki/Copenhagen#Etymology