Fastest Account Leveling (1 -> 300 in 39:20:12)

[PeuDoki]

174,275,500,000XP is needed for level 300
1,363,550,500,000XP is needed for level 400
39,840,560,500,000XP is needed for level 500

This means the same party would get you to level 400 in one more day and to level 500 in one month.