I’ve been experimenting with oversized items because people tend to not sell them as much and I’ve gotten good at packing large things safely. I like selling electronics even broken ones to keep them out of the landfill. I’ve got a stack of hard drives I need to wipe and sell
Same with electronics, just stay away from VCRs because scammers buy them and swap out parts then sell on Amazon. I always sell those on FB marketplace. I haven’t done any flipping in awhile and have a pretty big death pile at this point. I’m sitting on a few hundred new old stock vacuum tubes that I need to go through and probably do a bulk sale as most of them aren’t worth very much. Other than that my most recent sale was a AGP Nvidia quattro card from my personal collection that I sold for nearly $200. Iirc I paid about $30 for it a few years ago before people were really aware of them for vintage builds.