Enter a silver and gold price to automatically calculate all prices in a Cubecart silver and gold shop.

Enter a silver and gold price manually into back end of Cubecart, or into the database, to automatically calculate all prices in a Cubecart silver and gold shop. My site is bullion-cube.com. So far I've done the site set up and some customization myself, but will need help with this one. The formula for the calculation is: metal weight in troy ounces x metal price + premium = sale price I have the metal weight, same as product weight, already listed, you can see in product info / specification tab. However it's measured in kilos, because cubecart only has pounds or kilos, so I went with kilos. I tried to change the weight units to ounces, but could not figure out how to do it. Btw 1 troy ounce = 0.0311 kilos. If you could change the units to oz first, may be easier because you'd be working with unit 1 for most of the products instead of the fractional number above, and would look better too. Most of the products are 1 oz weight. So the above formula would either be current weight in kilos x US$ per kilo or normal weight in ozt x us$ per troy oz. Both prices are on the site, click link below colored cube. The above calculation gives the metal value of each piece, next add to that the “premium” for each item. I can give you a list or do the data entry for this. Btw they will change from time to time, so I'll need to know how to change them. Regarding price feeds, I prefer to enter the current silver and gold price myself. Btw, I'm working now on adding a few more items to this store before we start this project. Will add 5 Ag to Australia and 4 Au to Gold, after that the store will have a total of 16 silver in 3 categories, and 5 pieces in Gold. Thanks for your interest.