I phoned up the British agents for Niewiadow caravans (who made the Cadet
caravans/trailers in Poland, I believe) and they quoted GBP 225 (British pounds) for a Cadet front window, excluding shipping - that's about US$ 340 or CAN$ 425 at today's exchange rate (next week's rate could be different!).
I think the Captain has a bigger window, plus you then have to add the shipping which is very expensive from here to North America - at least $200.
A Canadian Cadet owner has had a quote for shipping a window in the last couple of weeks and declined to order when told how much!