PASSDROMIt's like 30 bucks just for the plate and I've heard good things about the site (Ponoko). It's more than I want to pay, but better than the clear.
CommunistWitchDrHuh, $15 per plate piece isn't too bad, really. How much are the other layers? If you just wanted the top to be opaque, it might be cheaper overall to get just the top custom cut and go with the standard case from this group buy. But that might not be what you're after, visually.
I'm not sure what Massdrop would discount for the case in this group buy, but I bought just a case in the last Ergodox round, and it was $80.