Instead of auctioning the Gabbiar, they could've forced Munch to incubate the eggs, so that they could have a "Gabbit Queen" and have both more Gabbiar production and more lung transplants. But instead, in the bad ending, the one who won the auction (presumably Tex), ate the Gabbiar (He probably didn't care about other Glukkons either). Or maybe it's just that Glukkons and Vykkers enjoy bringing other species to extinction and all the Glukkons will just quit smoking after the extinction of the Gabbits.