What Type of Movement Are SPX Options Pricing Into Jackson Hole (SPY; VIX; VXX)

From Option Pit:

...One of the nice things about the weekly options is that on a Friday event we can figure out exactly what the options market thinks the net movement will be after Ben Bernanke speaks.  The August options that expire tomorrow in the SPX are trading:

 

This implies that market is expecting movement of about 27 points out of Mr. Bernanke's speech.  If we consider that last year, with the market lower this speech moved the market 30 points, maybe 27 points isn't that much.  My thoughts though are that this is extremely over priced, especially when compared to straddles in the regular contract months.  Does it make sense to own a 27 straddle with 1 day left to expire or an 80 dollar straddle with 20 days left to expire like this one:

 

With all of the up and down garbage that has been going on in the market, I have little doubt in my ability to gamma scalp my way into a profit on the September straddle, a straddle that expires tomorrow might be quite a bit tougher to gamma scalp.  The one thing I have to worry about is how VIX futures are lining up right now.  There is a HUGE backwardation between VIX cash and September Futures...MORE