I traveled to North Korea through a travel agency of Dan Dong last year. It's cheap for native Chinese, bit expensive for Hongkongnese and Taiwanese, more expensive for Europeans and most expensive for Americans.
Actually it's very easy and safe to travel there. The pity is that you can't go there freely (only possible through travel agencies) and the most important activity is to bow to their leaders' statues.
But I really like North Korea. Cities are super clean; people are very friendly and civilized especially to Chinese since we are their brother country, haha.