Well all I have to say to this farce is that the person has far too much free time on their hands. I got some characters into the eighties without spending a dime, but gave up after that, the grind became horrendous at that point. Doing the daily instances 100 times became very unfun too.
Basically there are very few quests after level 70 and they provide only a small fraction of the experience for a level. So you are relegated to grinding and doing an instance a day for the daily quest, which is the same instance, over and over again. It only changes when you hit a level ending in zero.