Macroeconomics

I would like you all to visit this site http://costofwar.com/ and tell us what you think.  

There is a button at the bottom of the page titled "see the tradeoffs" . 

Click on it and explore it., you will find it quite eye opening. 

In your discussion, I would like you to explain how this helps or does not help in our understanding of the concept of opportunity cost. 
Can you compare it to something in your life where you see opportunity costs clearly