The question which I am asking is a bit complex. I didn't get any idea how to achieve this in Magento. I am developing a Jewellery Shop. Base product is Gold and Diamond jewellery. So what I want is instead of setting prices for individual products I want to apply a formula. I will set a rate of Gold and Diamond. Then will create the products made of Gold and Diamonds and set their weights individually. So the selling price of those products would be Rate x Weight = Item Selling Price.
Any one is having the answer please help me.