It is clear that N. Korean regime is economically squeezed. Interesting things develop when it happens. Aside from finding desperate and creative ways to get new sources of revenue, they relent on their grip on domestic markets so that general population is better able to fend for themselves. This was the case back when the massive famine swept the nation in 1990's. Regime realized that they could not feed their people and let them fend for themselves, which led to birth of limited (unsanctioned) markets in the country side.
On the other hand, N. Korean regime tends to tighten its grip on markets when sanctions are loosening and economic hardship is easing. It is a kind of ironic way the economic sanction works. N. Korean state inches toward accommodating markets only when it has no other choice.