Do you brown bag or buy your lunch?  The answer could make a significant difference in the size of your bank account!   Too busy to make a lunch before you head to work?  How does $3600 sound?  That’s what you could save in just four years if instead of buying that $10 lunch everyday, you ate out only half as often every month.  Want to see what your savings could be?  Check out Bankrate.com’s lunch calculator.