How to query Prices?

in Development
In Prices:
"Prices": { "ItemPrice": [ { "amount": "149.95", "useTypeID": "1", "useType": "Default" }, { "amount": "0", "useTypeID": "2", "useType": "MSRP" } ] } },
How can I compare the Default with the MSRP please?
If Default < MSRP & MSRP != 0 ?