In my quest to add every country that ever issued paper money to my collection I have purchased a completely work out old banknote from British North Borneo (Malaya area of Asia). This particular note is from 1938, though British North Borneo has issued a few issues of this denomination. Unfortunately I had to cough up $51 for this banknote, but that is how it is with British North Borneo. Supply is low, demand is high. This one might even turn out to be a decent investment in the end, considering scarcity of such notes. Ugly, but valuable ;)

British North Borneo p27: 50 Cents from 1938