How to Dupe runescape money:
Here is a secret on how to double your money by smithing!
To double ur money, The Requirements are :-
Level 35 Smithing
Dwarf Multi Cannon Quest Completed
and a bit of patience
Once You Complete the Quest, Please buy a Cannon Ball Mould.
You can buy this cannon ball mould at the entrance of the mining guild near the monastery.
All you got to do is to talk to the the dwarf in the room.
Once you got the mould , You can start a process to double ur money.
OKAY, Now to double ur money, all u gotta do is Mining/Buying ,Smithing and a bit of Merchanting.
Eg :- If u got 100k, Buy 500 Coal ores 150gp each for 75k. Then Buy 250 Iron ores 100 ea for 25k. Here you spent all ur money.
Now to double it, Smelt all the ores into Steel Bars.You get 250 steel bars (According to the example).Once u get the steel bars, start making cannon balls out of them . You can make a cannon ball by using a steel bar with the furnace with the cannon ball mould in your inventory. One Steel bar Gives out 4 Cannon Balls.So , the 250 Steel Bars Give 1000 Cannon Balls. Sell all the 1000 Cannon Balls for 200gp each and Finally You will get the Doubled Money.
You spent 100k and u get 200k in return.Hurray!!!! You have DOUBLED your RUNESCAPE MONEY. This trick can be done on millions also. You can double even Millions of Money!