from having a side hustle (ebaying old collectables I no longer have a need for) it's that you should never be that put off of selling something online because you're worried about shipping it. Chances are, there's an empty box around your home and some packaging material you can use. Old newspaper ads are fine. If you get the address label through ebay, you just need a half-decent printer.
Like if you know for certain that you don't have packaging materials and that getting them will be very time-consuming or costly, then yeah probably don't so you don't risk shipping something off too late for a buyer's taste. But it's not terribly hard to come by good boxes and such. The most difficult thing is probably racking up enough feedback that people are willing to purchase from you.