I had an issue like this arise about a month ago in a sale from an International buyer, but he wasn't Vietnamese.
The only thing I will add is that I learned to ask where the perspective buyer lives now. In negotiations, he sent me an USA address, so I assumed he was USA, and quoted the price accordingly. I was surprised to see a larger than expected bite taken by PayPal, only then did I realize that he was International buyer using a USA address. Had I known, I would have quoted a higher price to cover the higher International PayPal fees.
When you're talking thousands of dollars, that little extra 1+% adds up.
Lesson learned. When negotiating now, I ask the buyer more questions.
To give a proper quote, you can't make assumptions.
The only thing I will add is that I learned to ask where the perspective buyer lives now. In negotiations, he sent me an USA address, so I assumed he was USA, and quoted the price accordingly. I was surprised to see a larger than expected bite taken by PayPal, only then did I realize that he was International buyer using a USA address. Had I known, I would have quoted a higher price to cover the higher International PayPal fees.
When you're talking thousands of dollars, that little extra 1+% adds up.
Lesson learned. When negotiating now, I ask the buyer more questions.
To give a proper quote, you can't make assumptions.