Why drawn comb is never thrown away

A frame of drawn comb is the most expensive object in your apiary, and none of that cost shows up on a receipt. At roughly seven kilograms of honey burned for every kilogram of wax, a single deep box of comb, built from nothing, has already cost the colony many kilograms of honey it never got to eat, store, or sell before a beekeeper ever touched it.

Once drawn, though, that comb can be filled, extracted, and refilled for years: honey super comb, never used for brood, regularly lasts a decade or more, since it never carries the cocoon and propolis residue that brood-rearing leaves behind.

That is the whole case for holding onto drawn comb rather than melting it down: you keep the expensive part and only ask the bees to redo the cheap part.