You can still buy from Amazon as needed without Prime. The free shipping is still usually relatively fast, and they’ll give you a free or heavily discounted Prime trial fairly often. I try to avoid buying stuff on Amazon these days, but a lot of things simply aren’t available elsewhere or would be significantly more difficult to acquire. I haven’t had a steady Prime sub in at least a couple years, but they end up offering me a trial probably every few months. Hell, they gave me a full month for free a week ago (probably to try to drive up Prime Day sales).
I’ve basically always used the same pocket as my keys and I’ve never had problems with scratches. Admittedly, I have my phone in my pocket a lot less these days than I did several years ago, but that’s still almost a decade of experience…