If you couldn't transfer POs most of this flipping would go away. That's what really drives it because it cuts out one or two sets of shipping costs for the seller. Selling a PO that cost you say $650-$700 for $1200 where the buyer is also responsible for shipping is a big profit and the buyer doesn't wholly factor in.
Whereas if you pay $650-700 for the statue, then pay 150-250 to have it shipped to you, then try to sell for 1200 the buyer is more likely to want shipping included in that. And now you are barely breaking even. Even if you sell it for $1200 plus shipping you're clearing half as much.
It's the PO selling driving all of this.