Are you sure that it is just not that North Corea has a higher currency system? In Viet Nam I think it was like 16,000 dong to equal one USD, but 16,000 d will not buy you anything (besides maybe a packet of gum). It may have changed, I haven't been there in a while. I don't know why the currency is like that there (100 d equals a few cents). It is a lot more confusing.
Good advice about precious metals and land though. In Viet Nam they say "Land is more precious than gold".