@kitsunegames only the highest xp earned is counted. so if you earned 400 at first, then 450 the next time, only 50xp will be added, not 450xp. it prevents ppl from leveling up by repeated grinding at the same level
You might wish to reconsider how money is earned at the end of the game. I discovered, since end profit is based on total hp + damage dealt, at around sector 3 level 12-13 over $8000 can be earned on level 1 which takes about 5 seconds. It's almost equivalent to cheating and takes away the fun of the game.