Custom Pricing for Variable products Woocmmerce

I am developing a bakery website using Woocommerce plugin. Right now I am using simple and variable products. I wish to add an attribute of "weight/pounds" to cakes (Simple and Variable). I want to customize the price calculation of the product page in a way that if a customer selects 2 pounds, the original price should be added to the cart, let's say $8, and when the customer selects additional attributes, for example sprinklers, decoration, message, etc. the cost of these attributes should be multiplied with the value "2" (the pounds he selected) and added to the original $8 cost. Right now, everything is simply adding up. There's no way to get the value of the pound attribute chosen, multiply it with the additional cost and add the additional cost to the original cost. I have searched forums and haven't found anything

via Chebli Mohamed