you need 100K to start off
wait for the price of say superior vigor or absorbtion to be high.
open the trade window with the rune trader, then LEAVE it open for like overnight. in the morning, when more people are online, the price is likely to drop for these items. aslong as you dont refresh the trade window, you can buy a rune off someone at a reasonable price and immediately sell it to the trader for the original price when you opened the window. quick money