You know, I posted those three topics about duck (here, here, and here) and I negelected to get around to the choicest morsel available — the fattened liver, or « foie gras » (pronounced [fwah 'grah]). This is the delicacy that ducks are raised for.
Intermarché had two grades of foie gras on special last week. The first is just standard grade, called tout venant — the ordinary stuff. At just over $11.00 a pound, it's affordable, I guess.
The higher grade, called extra — which in French means something like "choice" and is probably short for "extraordinary" — goes for $15.30 U.S. a pound. For the amount you are going to consume — very little — you might as well go for the extra stuff.
The two final cuts of duck you can buy, at the opposite end of the price scale, are the carcasses. One is the whole duck minus the breast filets, and it's called a paletot, which means "the back" or "the coat." You get the leg & thigh sections plus the wings, along with the back.
If you just want the back — and it would be good for making duck broth or stock — ask for the « demoiselle de canard ». It's for the stockpot, or it can be grilled on the barbecue for those who like to pick bits of meat off the bones. I have friends who think nothing is better than that.