Fix some translation

htdocs/langs/en_US/suppliers.lang

@@ -7,13 +7,13 @@ History=History
 ListOfSuppliers=List of suppliers
 ShowSupplier=Show supplier
 OrderDate=Order date
-BuyingPriceMin=Best purchase price
-BuyingPriceMinShort=Best purchase price
-TotalBuyingPriceMinShort=Total of subproducts purchase prices
-TotalSellingPriceMinShort=Total of subproducts sell prices
+BuyingPriceMin=Best buying price
+BuyingPriceMinShort=Best buying price
+TotalBuyingPriceMinShort=Total of subproducts buying prices
+TotalSellingPriceMinShort=Total of subproducts selling prices
 SomeSubProductHaveNoPrices=Some sub-products have no price defined
-AddSupplierPrice=Add supplier price
-ChangeSupplierPrice=Change supplier price
+AddSupplierPrice=Add buying price
+ChangeSupplierPrice=Change buying price
 ReferenceSupplierIsAlreadyAssociatedWithAProduct=This reference supplier is already associated with a reference: %s
 NoRecordedSuppliers=No suppliers recorded
 SupplierPayment=Supplier payment