then in all fairness, some compensation should be also paid to you by the seller for backing out on his word. What would have happened if he sent you the timepiece and later discovered it's true value, would he call the FBI on you for theft?
Surely as the receipt says in WRITING that all sales are final and should the buyer change their mind then they are subject to a 15% restocking fee, then there is obviously some breech of contract. If the seller had gone along with the sale and the next day you had changed your mind, the seller would charge you an extra $4000-$4700 to restock it even if he had later discovered the true value of the watch. I would enquire in the state of where it happened as to what the consumer rights are when it comes to a botched deal as in all fairness the same penalty should apply to both sides. that is 15% to whoever fails to honour their contract. Surely you should be entitled for some compensation for the expenses you incurred to wire the money and other fees which resulted in settling the deal. His ignorance for not doing his homework in finding out the true value of the watch and using this as an excuse was an act of desperation and in my country ignorance is no excuse of the law. We also have heavy penalties for false advertising. Then again, different laws for different places.
I do not want to sound biased, but it is worth trying to find an agreement where both of you meet half way where both you and the seller can learn from this as it would cost you a lot more if you involve lawyers. If the seller will not even reimburse you for the shipping and bank fee costs, then it would be worth looking into bringing your story to the media. It would be very interesting to see how Judge Brown or Judge Judy would react to this if it had happened to them as buyers!!!