Well i'm in Ontario, i was just at a swap this past weekend, call duck adults.. some were 20$(but i did not look at these birds, this was a sign passing by so no idea on quality) , i know some on a provincial board i am on that sell ducklings for 15$, i paid 20$ for the ones i just got at the swap. Definitely varies, colours, sizing etc..
I live in New England. I sell mine for between 20 and 40 per bird depending on quality. I have some whites from the Dave Touchette line. Around here the go from 60 to 100 a pair. My ducklings usually go from 10 to 25. Some extremely high quality call ducks can go up to 100 and even past that.