Simple math:

10 contracts at .35 equals $350, cash out 10 contracts at 3.00 = $3K

Traders math:

100 contracts at .35 equals $3,500, cash out 100 contracts at 3.00 = $30,000

100 contracts at .35 equals $3.5K, cash out 100 contracts at 5.00 = $50,000

You would need to minus your brokerage firm commission...All in a days work if you were on the right side of the trade.