I think $15 is a lot for a duckling IMHO. I just bought an 8 week old blue magpie hen for 15. I got a white drake for 20. Do you have chicken swaps where you live?
For call ducklings? I don't think so, especially show quality ones. Considering that they lay so few eggs per year and they're difficult to hatch, I can understand the price hike.
I guess. People around here would never pay that much for ducklings. I do plan to hatch in spring though and sell the babies.