Phew...level 89 normally is 23,690 xp, according to RS Wiki. I thought the lamp was only meant to give you up to 23,690 extra from the bonus xp but it seems it might give an additional 300% from the bonus xp pool then? (23,690*4 =~ 95K). All i know is that i spent 400 keys and got 6m RC exp. Good game, girl's gonna kill me.