http://www.optionsprofitcalculator.com/calculator/long-call.html
a 30% SPY year isn't likely, but a 15-20% year is likely
The last time the S&P had a 34% year in 1995, it was followed by a 20% year in 1996 and a 30% year in 1997.
If it does go up 20% then you can make a 2100%-800% return...