Re:Home version (Score 1)

Check out the Sega Homestar Planetarium (marketed by Uncle Milton, the Ant Farm magnate, in the U.S.) It's the only thing that comes close to producing a quality sky, the rest are really just junky toys. I'd avoid doing a digital planetarium at home. As you mention lamp costs are high and the image will be pretty low res when you spread it out over the whole ceiling. You'll have dim stars the size of dimes.