I kind've thought glowstone was intentionally lower than it should be to allow everyone a good shot at getting a stack or 10. We seriously depend on it so much (hell, we line our
streets with it
) that if it was priced out of range it would just be bad for everyone. The world is prettier with glowstone.
Not saying I wouldn't welcome a price drop on quartz, but I wouldn't expect it. What I
wouldn't mind is the ability to buy a full block in addition to just the crystals. The 'nether stall' is full-up, but maybe the stall just to the left. Podzol is in two different stalls at two different prices, so removing one could leave room for a quartz block sign.