The problem with going somewhere else in China, is that I need an invitation letter from wherever I'm staying. So that will probably be even more trouble then getting a double entry visa. Been to bangkok and Singapore, Malaysia, Indonesia etc. before.

Since I'm going for such a short time, the prices for airplane tickets are more important then the price level in the country. So therefore I think Japan probably will be cheaper then Laos/Vietnam. Also I don't want a too long flight, because of the short time. How is Tokyo compared to Seoul? Tokyo is further and more expensive, but I think Tokyo sounds more interesting then Seoul.