This article explains why the Mint is interested in commemorative editions of coins: they make money; probably more than $4billion on the state quarters program.
I assume they are expecting something along the same lines from the Lincoln biography series of pennies though it will be harder, last I heard it costs more to make a penny than it is worth. But maybe their numbers show the direct collectors market compensates (and I wouldn't be surprised if at the same time minor composition changes are made to bring down the materials cost of making a penny).
But ultimately I doubt it costs that much to make the different coins.