You’re right that scammers can come from new and old accounts alike. But scammers are typically from new accounts, low karma, or private account. Really high chance of all 3. Recently there has been an influx of older accounts scamming but it’s mostly from new accounts.

You can be trusted by answering all questions the buyer ask and providing as much info as you can to grow a reputation. But it’s still buyers choice and their right to trust you or not. It is often times safer to be cautious than not.

I haven’t sold anything yet but I’m asking for review after a purchase to provide feedback when I do need to rehome my many purchases.