Several products in packaging = Multi prices

[Yoriel79]

Hello.

In my store I can add several products in one box. The packaging price is added in the final price. The limit are five products each pack.
I need that the final price, in front office, are equal to the sum of both prices.

Ej.

1 product-2.4€ + 1 box-1€ ------>TOTAL IN F.O 3.4€
2 products-4.8€ + 1 box-1€ ----->TOTAL IN F.O 5.8€
3 products-7.2€ + 1 box-1€ ----->TOTAL IN F.O 8.2€
4 products-9.6€ + 1 box-1€ ----->TOTAL IN F.O 10.6€
5 products-12€ + 1 box-1€ ------>TOTAL IN F.O 13€

6 products-14.4€ + 2 box-2€ ---->TOTAL IN F.O 16.4€
7 products-16.8€ + 2 box-2€ ---->TOTAL IN F.O 18.8€
8 products-19.2€ + 2 box-2€ ---->TOTAL IN F.O 21.2€
9 products-19.2€ + 2 box-2€ ---->TOTAL IN F.O 21.2€
10 products-21.6€ + 2 box-2€ --->TOTAL IN F.O 23.6€

11 products-24.0€ + 3 box-3€ --->TOTAL IN F.O 27.0€
12 products-26.4€ + 3 box-3€ --->TOTAL IN F.O 29.4€
...

How can I do it?

Thanks.

[Yoriel79]

Can anybody help me?

[Yoriel79]

Please, I need to solve this matter.