Agreed, if you buy it then it is your own responsibility to know that it requires more than just the money for the phone. Then again, some people buy expensive

Agreed, if you buy it then it is your own responsibility to know that it requires more than just the money for the phone. Then again, some people buy expensive cars and are surprised about the high price of spare parts. I guess many consumers like to pay a big amount of money for a single product, and not a big amount + 10 small amounts for a product that needs multiple other products during its life. Its like a phone case, we all wish it wasn't necessary to have one, but many people buy cases because the phone needs it to stay nice/safe. And I don't think there is a solution readily available that makes phone cases abundant for those people.