I can’t even ship an engine across the country for that price... they’re selling the engine with shipping and sending it across the world! 
This is the Chinese way of doing business. Watch out! But, I respect the quality. The mass-produced parts are really great. I have a simple Stirling engine myself, which needs a cup of hot coffee or tea as a source of energy (heat). Put on the table when friends are visiting us, it is an eye-catcher.
Jürgen