I've been on both sides of your anquish. I tried on three occasions to buy a head from Australia. Once, I tried when I had a friend vacationing in Australia and he agreed to bring one back if I could arrange the purchase. The particular individual I was dealing with on e-Bay would not, under any circumstances, box and deliver the head 30 miles to the hotel or even mail it to the hotel. He said local pick-up only and he meant it. I offered him $100 over and above his gas expense and he still wouldn't do it. Now, that's not typical of Aussie people. It was just my bad timing that Mr. Poopy Pants was the only with an Aussie head setup on e-Bay at the time.
Speaking purely from an individual point of view, it is a lot more trouble to ship to another country than it is to ship in your own country. Even shipping something to Canada from the US requires additional paperwork other than just a shipping label. I've sold parts to my fellow car enthusiasts in Canada and, fortunately, FedEx guides you when you use their online services to prepare shipping labels. The US post office is a great help in getting things shipped to Canada.
The problem in shipping from the US to other countries is not only the extra information and procedures needed to ship, but the money acquisition. I sold an intake manifold to an e-Bay bidder located in Poland. My bank or credit union would not accept a check from Poland, PayPal would not allow him to establish an account, I had no way of accepting credit cards, and Western Union wanted to charge him a fee larger than what he was paying for the manifold. I worked with him and was patient. He e-mailed me and told me he would think of something.
One week later, I received a letter sized envelope from Poland. I opened it up and there was $185 US cash in the envelope. That was the amount needed to pay for the manifold and ship it through the postal service. I was totally surprised it made it to my box because it was obvious the envelope was full of cash. I e-mailed him and told him I had the money. He then sent me instructions on how to complete the paperwork at the post office to keep him from having to pay duty fees, etc. This episode sums why most of us, who are not businesses, do ship overseas.
If I ever sell anything else to someone overseas, we will have to negotiate a fee in addition to shipping and currency charges. It takes more time on my end. To ship in the US, I box it up, do my labels on FedEx or DHL online, and wait for pick-up. The best help to shipping to someone in another country is for that person to be able to tell me exactly what the procedures are and what paperwork (and how to complete it) is needed to get it there.