I ship several hundred packages containing Antique glass every year,, average insured value is probably $1000 ish but I ship many worth up to $5000. I always ship USPS priority insured and I have never once had an item arrive at a customer damaged.

Sure there's some luck there, but IMO it's all down to how it's packed. I always use plently of 1" bubble wrap and packing peanuts. Glass should always be double boxed with at least 3" of peanuts between the object and wall of the inner box (more if the object is heavy). I place a red FRAGILE label on each facet of the outer box.

I've had several glass items shipped to me by USPS that have been damaged due to rough handling & poor packaging, and on the whole, USPS have paid the insurance claim. When they didn't, and the seller refused to refund my money, I have always been able to file a successful chargeback with my Credit Card company.

I would never ship a fragile item by UPS,,, they carry much heavier objects in their trucks than the USPS and even well-packed glass objects have arrived at my house utterly crushed. I know of at least one large auction company that has completely dropped UPS due to their rough package handling and refusal to insure ANY international shipment of Glass or Pottery against damages in transit (correction,, they will insure it,, they just won't pay any claims).

Someone once gave me this advice about shipping glass: When you pack something,,,, ask yourself if it would survive a 10-foot drop onto concrete from any angle.

That advice has served me well I think, and I rarely have to deal with the beaurocracy of the Post Office over claims.