The quickest way for money in non members is the following: get your mining to 40 (30 is the minimum but 30 will be very slow) and get 200 coal. then get 400 iron ore. You will need 30 smithing as well. Smelt 2 iron ores and 1 coal ore to make a steel bar. The bar is worth around 700-780 gp. If you want to save 20 minutes you can sell the coal ore and the iron ore but will only make 90gp for 1 iron ore and around 180gp for a coal ore.