Quote from just21:
$100,000, i'll toss you for it!
jokes aside, you erred in your calculation. What you don't factor in is the time premium. For example, The S&P june 1300 calls trade for $30. The June 1350 calls trade for $11. Now what does that tell you?
If you really think it's a 66% chance of the S&P staying in between 1240 and 1300 until end of June, you should sell those calls, and the puts all day long. You'd be rich! The odds are in your favor, according to you.