If you blew all your money on your kids' back-to-school budget, here are three things you should be able to save some money on in September.

Mattresses.  They're always a popular sale item for Labor Day, along with other furniture and appliances.

iPhones.

Plane tickets.  According to a study on holiday airfare, prices for plane tickets over Thanksgiving and Christmas will increase throughout October, November, and December.  So if you can book now, do it.

And a couple items you should hold off on buying are:  TVs . . . which will go on sale in November for Black Friday and January for Super Bowl . . . and Halloween costumes, which will get marked down the closer it gets to October 31st.

Market Watch