Creation of Calculator app to calculate daily prices

General information for the app: The app that calculates the price of customer's asset Kind of development: New app from scratch Num. of web pages/modules: 1 Description of every page/module: Homepage should contain a calculator that would allow for a customer to choose between 2 categories jewellery or scarp, each section would have to have two inputs. Inputs being weight and percentage. However, the tricky bit is, that I need a solution to be suggested, for the non-customer info entry. In the app how to enter the daily metal market prices. Description of requirements/features: Calculation mechanism that has appealing design and ease of use. Similar urls: http://www.goldcalc.com/ Extra notes: