Insurance, and a later insurance claim requires double boxing.
If you box and buy the insurance, you can keep the cost lower for buyers, however, because you paid for the insurance, any claim must be dealt with by you. It takes time, not always successful.
a way to transfer the cost and responsibility to the buyer:
1. measure and weigh the unit unboxed.
2. find local UPS that ’packs and ships’. (they all do not).
3. In your ad, give size/weight/UPS tel. # to the potential buyers.
4. They get cost quote from UPS, they pay UPS themselves, all falls on UPS/Buyer.
5. you drop unpackaged item at the UPS office in their name.
Done.
I have bought two things and made my own arrangements with UPS this year. Shipping costs more, but I got a great deal from two ’local pickup only’ sellers, and UPS packs them properly because they are responsible for any damage.