Inside the shop, standing beside a desk, is the shop proprietor, Moneybags. There is a sign giving the Current Exchange Rate (CER). Below that is another sign stating the fact that the CER will change depending on the demand for Gems/Orbs
CER:
Gems ---> Orbs --- 100:1
Orbs ---> Gems --- 1:100
CER:
Gems ---> Orbs --- 100:1
Orbs ---> Gems --- 1:100