Actually my guess was based on possible tooling in the upper left field but the posted photo is quite low res so I guess they're just scuffs on an otherwise AU55/ 58 quality coin. I guess we just didn't expect to see such an AU 1800 $10 gold being sold for $300 on Ebay. I have looked at such types in real auctions at shows I've attended. The 1800 $10 alone actually sold for ~$18,000.
Generally not, but there are exceptions. One example that comes to mind is when the price exceeds $5000, and the transaction cannot be completed through PayPal. I'm not in the habit of spending $5K on a coin, but there are some who don't even bat an eyelash at that level. Under those circumstances, if I didn't already have history with the seller, I'd look into paying through an escrow service. That would have been beneficial back when this incident occurred, as it would have scared off the thief. Unfortunately, I had no experience with, or even knowledge of escrow services at that time.
Thanks to everyone participating in this thread. I appreciate your sharing your experiences, painful though they may be.
And eBay makes it almost impossible to contact them directly. It took 3 months for me to get $18.99 back on an item that I never received. The seller is still there selling away while he ignores my messages. EBay finally reversed the sale and posted the refund after three attempts by telephone, one each month.
Did you try Interpol. When I worked in the federal system we referred many things to them and depending on the price threshold they may accept it.