When buying a used imagesetter, you have to make sure that you get support for service and parts. I personally know several companies that purchased second hand imagesetters from sources that could not provide after sales support; and they regretted their purchase later on.
Here is a list:
1. A company owner purchased an imagesetter from a friend who closed shop to migrate to the U.S.. He never got the unit running.
2. A printing machine dealer imported an imagesetter for his press. After 3 months, the unit broke down. He never got it repaired.
3. A company bought an imagesetter from the ADB auction last year. Until now it's not yet running.
4. 2 companies I know imported units from the U.S.. They never got them running because of missing or defective parts.
There are more sad stories to share.
The advise I can give is to purchase from dealers that can provide the following:
1. units that have been refurbished and tested prior to delivery.
2. installation
3. warranty
4. support for parts and service.
5. good reputation and tract record.