Configuring fixed vendor fee per product

-- HikaShop version -- : 2.6.2
-- HikaMarket version -- : 1.6.7
-- Joomla version -- : 3.5.1
-- PHP version -- : 5.4
-- Browser(s) name and version -- : Chrome latest
-- Error-message(debug-mod must be tuned on) -- : None

I have hikashop and hikamarket set up that each vendor has it's own products. I have several cliënt groups who have different prices for the same product. I wish to configure a fixed price my sub-vendors get for their product without the client-prices having any influence on what the sub-vendors get.

I currently have the vendor price calculated on having a fixed fee for the main vendor. But is it possible to this the other way around?
Example how it works now:
For client A product price is 12 euro's
For client B product price is 11 euro's

If I set up a Vendor flat fee on the product for 5 euro's, the sub-vendor would get 7 euro's in sales when his products are sold to client A and 6 euro's in sales when is products are sold to client B.

I wish that no matter which client buys the product, the vendor will get a fixed amount for his product from the main vendor.

How would I do that? I tried to use the fixed fee entry. But for some reason the field order_product_vendor_price in the #__hikashop_order_product table would record the price for the consumer.
I am currently using this block in the product edit to maintain the fees: