...or download it for free
The Revenge of Dr. X is in the Public Domain so it can be legally downloaded for free, the torrent can be found at: http://publicdomaintorrents.com/nshowmovie.html?movieid=811 or you can just watch it online there or at Google Video, here: http://video.google.com/videoplay?docid=5074520914321662305&q=the+revenge+of+doctor+x
Enjoy!