With all the tens of millions of GP that you and everyone else has laying around? :P The difficulty in skills like construction, prayer, herblore, etc., isn't in the leveling process but in making the money, which is no easy feat for the average player. Once you have a lot of money, it's easier to make more, like merchanting on the GE. But yes that's also true. I just feel sympathy for the boringness of Runecrafting :/