Difference between quantum and quantus, -a, -um
In Orberg LLPSI in Cap 8.72 he has Medus asking the shopkeeper to show him a ring:
Medus: "Ille post te. Quantum est pretium illius anuli?"
Orberg explains: quantus, -a, -um = quam magnus
then in cap 31.53 we have Cornelius asking Iulius how much Medus has stolen: "Quantum pecuniae abstulit"
Orberg explains: Quantum = quam multum
Each of these two uses has an separate entry in the vocabulary. What's the difference between them?