well doing 10 to 80 will take so long that 1, you will be so annoyed of leveling u will quit or by the time you did it all, you would have a new expansion out. I would advise the 9 together at the same time, and just questing or w/e just kill stuff to level up. Although when i did it i only did 5, I coulnt imagine if I had to do it 1 by 1 to 80