Originally Posted by
eponymous_coward
Your budget is fine for Thailand, Malaysia and Indonesia. Japan and Australia are going to be expensive (especially Tokyo).
Beware of Australian prices as well. The pound is weak right now, and the dollar is very strong: 20 quid/night is about A$30, which will barely suffice for a dorm bed. Realistically, you'll need to budget at least A$100/day on bed, food, sights and local transport, with long-distance transport on top of that.
Covering both China and Korea in ten days seems a little ambitious, and flights up there aren't cheap either. You could save a fair amount of cash by spending that same time in SE Asia instead.