The following dovetail jigs are in excellent condition:
Keller 1500 Journeyman Dovetail Jig
Price £30
Full details here
Stots Dovetail Template Master
This is as good as new and complete with original box, instructions and the pin and tail board that I made to help you get started.
Price £30
A detailed informative review can be seen here
A series of video tutorials is available here