As long as it is something small/engine it is fairly cheap. Not that much more than shipping in the states, you will be surprised. The only thing is it will most likely sit in there customs for a few days. I have shipped several engines overseas and have had know problems.
Domestic, all they do is ask at the counter if it contains anything hazardous, liguid, etc. Sending worldwide, it's subject to being opened and inspected. It would be a good idea to get it clean and placed in plastic bags.
My father sold a boat to a guy in bermuda, it cost about 75.00 to send it. the guy asked if he could put a note in the boat stateing the value because they have almost if not over 50 % sales tax. lol