1) Search for used heavy machinery only on well known websites. Important is where in your country and how quick you can purchase spare parts and service for a second hand excavator.
2) Ask supplier for true information about machine condition. Ask supplier which repairs are required. Ask for transport cost to next port.
3) Send a friend or an independent inspector to check the machine condition.
4) Ask seller if he can provide all required customs documents.
5) Check with the dealer all options for shipping such as RoRo or containerizing of machinery.
We have a little blog where steadily info about our inspection work is posted. Please visit the site for info and entertainment: https://mevas.net/mevas-blog