Sock Management

Hi,

If you want to have different product page for each package, you could create a main product with the whole stock, and then in the package products, you could use the "bundled products" setting to add that main product to the package product and specify the quantity of that main product in the package.
The system will then calculate the stock automatically upon display and won't allow the customers to order more packages than possible, and also, when the package product will be purchased the system will update the stock of the bundled product.

Alternatively, if you want to have only one page with a dropdown to select the quantity of bottles, you could add several prices in your product with different "minimum quantities", one for each package and one for the main product.
Then, in the "quantity input" setting, select "show select by price" and it will change the quantity input field of the product to a dropdown and each option of the dropdown will correspond to a price.