Currently you can sell glowstone for $4 in shop, which means one glowstone dust is worth $1, which means one glowstone dust is worth a block of dirt I think this should be changed because glowstone is much more rare than dirt, and so should be worth more if you got some and you are willing to sell it. Excavation is also a way for people to get money, and as the shop is now, its practically useless.