shipping price for multipack products

Hi,

In the "formula" setting of your shipping method, you could write:

So that the shipping fee would be 7€ from 6 to 11 bottles and then 14€ from 12 to 17, etc.
And also enter 6 in the "minimum quantity" setting of your shipping method.

However, if what you want is to only allow purchases of 6, 12, 18, etc, then the formula setting won't help you.
Instead you need to create several manual shipping methods:
- one with a minimum quantity of 6 and a maximum quantity of 6 and a price of 7
- one with a minimum quantity of 12 and a maximum quantity of 12 and a price of 14
- one with a minimum quantity of 18 and a maximum quantity of 18 and a price of 21
...etc...
That way, the system will automatically filter the shipping methods on the checkout and only display the ones matching the current stock in the cart.
And when the quantity of the products in the cart is 5 or 11, no shipping method will be available and the user will get presented with an error message which you can potentially customize with a translation override to tell him to add a total quantity of bottles which is a multiple of 6.