Check out this price for a new ZDZ-80 single cylinder engine, $430. Here is the web site:
http://www.zdz-motor.de/html/zdz80rvus.html The price is shown in the Euro so you will have to use a currency converter. I bought one last year and received it in one week from Germany. It takes longer than that for me to receive a package from the west coast. James Goss