That about sais it, but you left out that there would probably be an increase of higher level mages and fletchers because of the drop in nature runes This would lead to people wanting more higher level spells and suddenly there's a major inbalance in the pking triangle because of the massive amount of new mage pkers. People would be practically begging Jagex for a new magic spellbook with offensive spells, even after the new Lunar magic update, so in order to keep order there would have to also be a new, highly effective range set, and melee set. Which as we know from the barrows has an even greater effect on the economy than the primary increase in runes. But this is all just speculation, crazy as it may sound :