Hi Ançay,
I didn’t understand why shipping costs are involved in this, because this plugin has nothing to do with pricing or shipping costs, it will allow you to control quantities that customers can buy.
From what I understand, now you have 2 types based on how much space these bottles take, the plugin (in its default settings) won’t allow these advanced mixes of quantities, but an option can be customized to give a “weight” to each type, and then calculate total weight in cart to match the desired/allowed quantity.
If interested, reach us at [email protected] to discuss further.
Omar