[abysmalpoptart]

xp per minute IS NOT constant, it is changing

it is based on some crazy ridiculous formula i can not tell you about. why? I HAVE NO IDEA WHAT IT IS

but i can tell you what are factors:

battle stats (primarily DEXTERITY)
level
busted minutes
(the exp amount goes up exponentially in the 600 minute range)

but, as zen put it, the easier the bust, the less xp u get. so a 600 minute bust at level 35 will probably get u WAY more exp than when you are level 50. this is a fact of life.

if i did the same 643 minute bust again now (wont happen), i'd probably get a fraction of the XP, possibly 5,000, because i'm many levels higher in all my battle stats and in actual levels