Lets say you cut yew trees for a living. Because of macroers the price of the logs are only "210gp" each. So, if you get 2000 logs at a week. You get 420k. Lets say all the macroers left runescape. Now the prices of yew logs skyrocket to 300gp, and Runes go up "x" number of gp etc etc. Everything will be more expensive. But hey, you can make much more money than before because now you get 300gp each log instead of 210gp. Thus. You are now "richer". So when you go buy runes, the prices did go up, but so did your income from woodcutting. So you are basicly not affected by all.