Here's a list of things you should and should not buy in September:
Mattress
Since it's a holiday weekend, many companies are offering significant discounts and freebies on furniture and appliances.
iPhone
Apple is rumored to release a new iPhone, which means retailers will likely discount older models.
Plane ticket
CheapAir.com predicts flights for Thanksgiving, Christmas and New Year's will increase after September.
Television
Don't buy a TV this month because you'll get a much better deal in November during Black Friday sales or in early February around Super Bowl.
Halloween costumes and fall decor
Stores will start tempting you, but try to wait until October when Halloween sales will begin.