not many canadians knows how to cook duck well.
so not many of them buy it.
thus the supermarket can't stock too many of them.
since they can't stock too many, they do not do a mass purchace from their supplier. The supplier thus won't give them discount. Hence the price would not be low.
销售不好应该便宜only happens when the supermarket overestimated how much the consumers need, and had gone ahead purchaced mass amount of one thing. Then they found out it is not selling, they are forced to lower the price to get at least some money back before the food expires.
in case of duck, they know not many people want to buy. But if they do not stock one or two every week, they may loose a few customers.