Right now the biggest problem is shipping costs. We've stopped using the United States Postal Service which had international shipping rates around $38 and it would usually get there in a week. The problem is sometimes it wouldn't get there at all and the USPS doesn't actually pay on their insurance claims. When they do it takes 2-3 months to get the money back.
Also we had a LOT of complaints about USPS tracking service on our domestic shipments.
So we've switched to UPS exclusively on the new website. The problem here for international customers is the UPS's cheapest "international saver" option is almost $85 to most countries! For UK customers we are going to set up a shop with Ben where we can ship just the modchips, then Ben can ship controllers from over there and save a few bucks. It might take us a little time to set this up.
I don't have any agreements right now with mod shops in Australia, so unless somebody knows how we can get UPS to give us decent international rates? :-(