If you're thinking about 3-boxing, and will need to level a new toon, then I strongly suggest leveling 3 new toons with the thought of what your 5-boxing team would look like if you ever to make the plunge. The last think you'll want to do after leveling 2 to 80, then 1 to 80, is move to 5 boxing and have to level another 2 to 80... I can almost guarantee you'll be burned out.