Product Cost With Reporting

-- HikaShop version -- : hikashop business 3.0.1
-- Joomla version -- : Joomla! 3.6.5

Hi,

I want to add a product cost option when i creating product. i found a thread that say it can be done by using custom field. but i would know that if i do by custom field. is there any possibility that the costs shows in total under sales report?

my client would like to know the cost of products that vendors upload, so that they can calculate commission from the margin of sales.
So he hope that the statistic can shows the cost of the sales by a vendor.