I completely agree, it's all about maximizing efficiency. Now one person may say, "I'm going to mine 10k pure essence for 50k mining experience then craft them into nature runes so I can make 3m and get 90k runecrafting experience." It's a good plan if you don't have much start up cash, but at my level it is an utter waste of time. 12 hours to mine the essence and then another 10 hours to craft it and all you get is 90k rc exp and 50k mining exp. Now if I wanted to make 3m and get rc and mining exp I could just buy 15k pure essence (You'd need to make 15k in order to get 3m profit because of pure essence costs) and craft it, that would take 15 hours and get 135k rc exp. Then one hour of powermining granite will get me the 50k exp I need to match the other person. So it should be obvious now which would be the better choice. 16 hours of work for 135k rc exp, 50k mining exp, and 3m profit is far superior to 22 hours of work for 90k rc exp, 50k mining exp, and 3m profit. The numbers are off by a tiny bit, of course, but you can still get the general idea.