I've opted for trade-ins just so I don't have to go through that extra stress of worrying about meeting up with a stranger, or mailing it out and never knowing if they do some kind of paypal claim 6 months from now. Whether that's worth the extra $100-200 or not is another thing though. I had a personal safety concern last time I sold something in person, so I'll never do that again - it turned out to be nothing, still sketchy.
I paid $800 for my M2 MBA last year (Best Buy sale + open box), my trade in offer for it is $610. It's absolutely worth more than that if I'm just selling it straight to another end user. They'd think there's something wrong with it if I offered it to them at that price. But I just have to keep in mind, Apple pays for shipping the device back to them, refurbishing it, and then resells it to still make a profit. At that point, I think the $610 is worth it.
It's kind of hard with trading in an iPad though. You most likely spent a lot of extra money on accessories like the Pencil, Magic Keyboard and screen protector which are useless with the new iPad. Apple doesn't offer any money for those. So in this case, it might be worth it to try to sell it or gift the whole set to a friend or family member. Seeing a family member continue to use your old device is always worth it even if you got no money from it, my mom still uses my old 2018 iPP daily, my husband uses my old 2020 iPP, my brother has an old iPhone, etc.
