I had an international twit give me negative feedback because he didn't know he had to pay import duties. He somehow though it was my fault that this country sets and implements those charges. We messaged back and forth several times and I explained import duties have nothing to do with a seller or eBay. He wanted me to reimburse him the fees to which I said no, so he gave me negative feedback citing high import duties as the reason.
i stopped doing business with international customers for this reason. if something gets held up in customs, shipping takes longer, etc the buyer always seems to blame us sellers for things that are otu of our control and thing that will happen to any international items they buy.
heck another problem depending on the country some countries are notorious for people stealing goods out of the mail. when i was living in mexico before i learned my lesson i had my mom sned me some clothes and items, nice stuff. when i got the box my clothes had been taken out and replaced with dirty underwear, newspapers, etc.
on ebay your forced to accept paypal however on my own website where i sell stuff ill accept cashiers checks and let customers know once i ship and provide tracking i take no responsibility for mailing time, lost packages, problems with customs. most customers are okay with this as well b/c im one if not the only one of those in my industry who ship internationally