Feature request: product margins rate fields and calculation

[DjMagicFingers]

This is a request to include an additional field in the product table that will hold the percentage of how much to add to the cost-price to create the sales-price.

For example, if I want to earn 10% for a specific product, I will fill in the "margins" field the value "10" so the "sales price" field will show the cost price plus the margins already calculated.

I think that you already have the mechanism - it is quite like calculating tax, only it calculates the final price to sell the product while relying on the cost price and the margin field.

A good addition to this can be a global field per product category where you can set a global "earning" percent you wish to apply to all products that are on the category by default, if not entered manually.