Canned salmon or caviar could also come in a stock tin or jar with a label. How about fine spirits with a custom bottle. Is that a better example? What I am getting at is the higher you price point and perceived value you have more money to spend on pkg.
It is all about price. How much does your raw product cost, what are conversion costs, how much do you plan to sell it for, and what are you profit margins. All of this should be able to tell you how much you have to spend on pkg.