In order to use this process, you must know that the more money you are willing to
spend, the more you will make. The basic of this strategy is to purchase runes at their setprices from Rune shops and then resell them back to the players for a much higher price.For free-to-play players, there are two rune shops, one in Port Draynor and one in southeast Varrock, in which you can use this process to your advantage. Know the price of the runes that other players are willing to purchase them (visit the Runescape forum if you are unsure of a price), purchase the runes in vast amounts from the shops (remember that with the decrease in stock comes the increase in price, so world-hop if need be), and then simply find a buyer who’s willing to purchase them at your set price.

The Magic Guild, located in Yanille and only available to members, holds stocks of
elemental and rare runes in its shop on the second floor. These runes are sold at a price much cheaper than they are usually in other rune shops. However, to gain entrance in the Magic Guild requires a magic level of 66, so it might take awhile before you can use this money-making process on this shop.

Here is an example for using this method. As you may know, law runes are worth
around 300-500gps for most players, and the cheapest price for law runes in the Magic
Guild Shop is 240gps. So, as a benefit for being a member, you are able to buy a large
amount of law runes from the Magic Guild and sell them to other players to make more
money. You can earn bundles of hard cash using this method within an hour. At the same
time, you can also buy other runes, such as nature runes for around 200gps+ each, and
then sell them for more than they are worth in the shop to the players. Using this method can rake in 75-100k per hour with just only using law runes.

Hint: Another rune shop where they sell law runes for 240gps each is in Marim, on the
island of Ape Atoll (Monkey Madness quest completion required). Also, world-hopping
around the servers will enable to buy the runes much quicker and cheaper. Turn off your
private chat if you don’t want your friends to be bothered by your logging on and off.