Combined purchase options

We are going to add a new url to our website with a type of paper bag.
From this article we are going to have 3 models (sizes).
How can I make it so that a customer can buy any possible combination, from 1 package (or more) of a single to a package of each model or only two models or however the customer wants?
My idea is to be able to make combinations to be able to get a good price for packs, since the cost of transportation decreases.
I don't know if I have explained myself well.

Hi,

How will the price change based on what the user selects ?
Could you provide some examples ?

I detail several examples so you can understand the idea.
- Only 1 size small : 10 €
- Only 1 size medium : 12 €
- Only 1 size big : 14 €
- Combination 1 small and 1 medium: 20 €
- Combination 1 small and 1 big: 22 €
- Combination 1 medium and 1 big: 23 €
- Combination 1 of each model: 30 €
But you could also make other combinations of 2+0+1, 2+1+1, 1+1+2, etc.

Hi,

What happens with combinations of more than 1 ?
For example, if I purchase 3 size small, is the price 30€ or lower ? If lower, what price ?
If I purchase 3 of each model, is the price 90€ or lower ? If lower, what price ?

Hi Nicolas.
Of course, that is the basis of my question.
I want to consider several combination options, each with its own price.

Hi,

Mmm. I'm not clear on what you want.
One solution would be to have 3 characteristics : small, medium and big.
Each one with values : 0, 1, 2, 3, 4, ....
I would recommend not going too big on the values.
Then, add the characteristics to the product, add all the combinations as variants, and for each variant enter the price you want to charge.
This will work fine up to a few hundred variants.
After that, the loading of the page will likely crash due to the amount of variants to load and process on the frontend.
So that means you'll be able to go up to 5+5+5 but not much more.
The advantage of this solution though is that you get the maximum flexibility possible as you can set a specific price for each combination without having to enter rules like -2€ for 2 products in the cart, -4€ for 3 products, etc, which apparently won't cut it in your case.