Is It Riba?
“ A buys apples from B at $10 ” is a trade, not a loan. A loan would be “ A borrows apples from B “. I can’t comment on the latter part of your follow-up. We’ll have to look at each hadith separately to figure out it’s credibility, context, as well as applicability to this discussion.
True we know the concept now we need to learn how to apply it to the real life scenarios.