The cost for each DVD would be more than the average income of a normal North Korean.

I remember that a American POW who defected to North Korea ended up playing the bad American in all the movies!!
He also ordereed the kidnapping of Japanese (from Japan) to help teach the language to North Koreans. May of them were considered dead, untill they were revealed after 20+ years in North Korea. I believe many of them returned home after Japan put pressure on North Korea.