Thanks guys for all the kind words and supports! If I'd known that the refund would've been credited to my AU credit card right away, which I'd know that it will resulted me in a few hundred bucks loss, I'd probably chase it up with the credit card company since the beginning because they would've helped me out in AUD I suppose. I just thought that I was able to keep the money in my USD PayPal wallet. But apart from that, I was obviously trying to resolve the matter via eBay first because it's where the transaction took place.
I did not contact PayPal at all, because in order to open a dispute in PayPal, you cannot have any open cases in eBay. If the eBay case were to be closed in favour of the seller and there's nothing else that I can do, that's when I would go to PayPal as well as continue making my case with the credit card company.
I've heard about PayPal refunded both seller and buyer in some situation, but that would not satisfy me. I mean, I'd be more relax that I'm getting my money back for sure, but I'd still try do to whatever it takes in my power to expose the seller for his scam attempt. Someone like that does not deserve to be left at peace until the justice has been served.
That said, I'm also on the fence about the seller being named and shamed here. From my understanding from his messages at the beginning when I told him that there's a problem with the watch, he is just this rude guy in his 60s and watches aren't regular items in his listing. Most of his listing as well his previous sold items are more like common antique homewares. I remember him saying stuff on how he was gonna get his nephew to come and help to deal with me about the refund and that sort of thing as well, so I kinda have my suspicion that the nephew might be the one who gave him the idea to scam me? That's why judging from his feedback, I was quite surprised that this happen, because I always buy the seller.
But regardless, whether it was him or his nephew's idea, he's still the one who did it anyway at the end. I don't hold grudges as well, this case has been resolved for me now. It'll probably worth a shot calling my credit card company one more time tmrw, see if they can cover me on the forex fee? Though I think that might be unlikely, so I'll just accept the loss as a lesson for myself. And let's turn that lesson into a positive thing where all of us can learn from this case!