Minimum purchase on a website -- 2

Hello. We've a build your own box page. We sell 10 different products, and we have a minimum purchase of 10 items on the store. Now, we've created a pack that by concept has 20 snacks on it. But, shopify don't recognize the pack has 20 items. Shopify recognize it has 1 item and don't allow people to move on. Of course, we don't want to make people by 10 packs - it would mean that a person will buy 100 snacks. So, we've worked with a previous developer that made us a tag that allows the person to leave the website with only 1 pack in the cart. But, now we want to duplicate this to another products. So: -> We want to keep the rule of minimum purchase 10 items, and also keep the actual product that skips this rule. -> We want to be able to duplicate the product and make sure that all the duplications follow the skipping rule. Because this is something that is already done in our website, we just want to make sure that this works for another products that we choose, and not only for that one in particular.