What’s your business mode? Are you doing private label, retail seller or arbitrage? Someone else commented a very informative response. I would go through that to get a better idea. I’d still get a label printer just in case.

I personally don’t trust my supplier enough to send the correct amount units, proper package of delicate products, damaged products and missing or damaged barcode. I have everything from my supplier sent to my building, look though everything and make sure it checks out. From there I send it to Amazon. Yes it’s more work, but you’d be surprised how unprofessional some suppliers are. If there’s a problem it falls on you. Good luck