Several shipping prices for products?

-- url of the page with the problem -- : mywebsite.com/mypage
-- HikaShop version -- : Business 2.2.3
-- Joomla version -- : 3.2.1
-- PHP version -- : x.x.x
-- Browser(s) name and version -- : XXXXX x.x.x
-- Error-message(debug-mod must be tuned on) -- : Error_message

Hello,
I have 2 categories of products in my shop. For one of them I want to add shipping prices for each piece they buy.
By example 1 piece = 2 euro shipping, 2 pieces = 3 euro shipping etc.
I can do this with shipping methods. But not in combination with the other category. Because the other category is always 3 euro for an order. If someone buys 2 different articles from the last category he still pays 3 euro for the whole order.

I have tried it with 2 kinds of shipping methods. But it wont work.
When I set one shipping to "prices by product" (for the first category) and the other general shipping (3 euro) for the second category not 'prices by product". Then the general 3 euro works and not the other which I have set by the several products where I want to have them won't work.
When I do set both shipping to 'prices by product' I get for each product from the second category in 1 order extra shipping (3 euro). And that is not what I want.


Hope someone can follow my story and has an answer to help.
Thanks.