Did you use a Tradesy label? I'm wondering because I also sell higher-end items, and all of my USPS packages above $500 require a signature. I also ship and insure packages with Fedex and they have the same policy - any package valued above $500 requires a signature. I don't understand why would a delivery driver leave this package on a porch?...
I once had a buyer who contacted me and asked whether the bag I was selling came with a strap. I said yes. She was super happy about it purchased the bag. Later I got contacted by Tradesy cc saying that the buyer said there was no strap in the package. I knew the strap was there because when I packaged the bag, the strap was attached to the bag. The buyer said that when she received the package, it was severely damaged and that probably USPS stole the strap (she even sent pictures of the package to Tradesy cc). I didn't believe her for a second... you don't just inquire about a strap, and then the strap goes missing. It was a $3000 handbag. If I were stealing something, I would steal a bag and a strap, and not just a strap. I told that to Tradesy cc. I don't know what happened in the end, but they gave me my money for the bag. There are different types of scammers out there...