I received a watch box from a seller in china not long ago, and it arrived with the glass top all broken. The box and the internal box and the watch box were very well wrapped, but the glass still managed to break. I dont and didnt blame the seller for this as it did appear they went to some effort wrapping it.

However with glass, it doesnt take much, it just has to be a jolt or a sharp drop to break glass and ceramics.

But, i contacted the seller and they went out of their way to help me, and we ended up deciding on a partial refund to cover the cost of getting new glass. So that i would not have to pay for postage back to china.

Because the problem i see with your vase, is that if you cant come to some sort of satisfactory compromise with the seller. And go through the paypal dispute, you will be forced to send the vase back at your expense, which might end up costing more than the item is worth in the first place.

Good luck and hope it all works out well.