I sold a bunch of equipment this year, including a turntable and a big-arsed pair of Thiel 3.7 speakers.
It seemed to be to be a sort of joint-responsibility, depending on how the sale is done. For the speakers, my add said buyer responsible for shipping. Now...if the buyer decides to cheap out on a form of shipping with higher risk...is that really my fault?
In this case, I supplied all the information I could to the buyer as to the best shipping practices to increase the likelihood of safe shipping. I went to the speaker manufacturer to ask how they ship, and recommended that to the buyer (who chose that method - i.e. pallet shipping, and strapped on the way suggested by the company).
I took care of my end of the bargain. As per usual, payment was made first. Now they were his speakers.
I meticulously documented with photos the condition of the speakers before packing, and documented every step of packing for each speaker, showing now safely they had been packed, no damage occurring on my end. And sent those to the buyer. It was now up to him to arrange the shipping. Again, given I had done absolutely everything I could, and shipping choice was up to him, it seemed to me (and to the buyer) that I did my duty, now he does his.
Everything went great, fortunately.
As for the turntable, I wasn't going to ship that thing, so it was local sale only. That really helps. My pal who has sold many more items, including turntables, advised me on how he does things. As he put it, the last time a guy came over to pay for and pick up a turntable, the buyer wanted to see the turntable of course to inspect it (not just encounter it all packed up). Once inspected, my pal suggested if it looked fine, time to pay. Once the money had changed hands, my pal said: "So, would you like some help packing and carrying YOUR turntable?"
;-)
I took that approach when I sold my turntable. It's good to have clear boundaries and agreement.

