One of the best place in my time of playing Runescape would have to be Green Dragons. At a level of 79 they are easily killed and can generate alot of cash. To Take on a green dragon i would recommend at least 55+range and 50 hit points as they can hit fairly high on lower levels, Or you could try the much easier way by simply buying a Dwarf cannon, saying you have completed the Dwarf cannon quest, once you have your dwarf cannon buy how ever many cannonballs you wont, recommended 1000 which makes about 1mil cash and can be accomplished in under an hour. But be warned this method of money making has its ups and downs because since Green dragons are located in level 16 of the wildy there a possible chances of revs, SO 2 MUST HAVES FOR LOW LEVELS ARE: RING OF LIFE AND A GLORY AMULET. This method has made me millions over the past and is the best possible way to make money in Runescape Happy money making :D