How to get the price from Trade agreements set for purch for an item

PriceDisc::findItemPriceAgreement(
                    ModuleInventPurchSales::Purch,
                    ProductsAndVariants.itemid,InventDim::find(InventDim::inventDimIdBlank()),
                    inventTableModule.UnitId,SystemDateGet(),1,inventtableloc.PrimaryVendorId,
                    CompanyInfo::standardCurrency(),vendtable.PriceGroup);