6. Fresh Food

Finally, you might not think of food purchase in the same way you think of car or lawn mower purchases, or even clothing, but the Fall is a good time to find the best prices on locally grown fresh foods, MacEahern points out, since harvest time means lots of farmers have lots of produce they're trying to sell at the same time.

"It's a great time to shop at farmers' markets," said MacEahern, who lives in Tacoma Park, Md., a suburb of Washington, D.C., where farmers' markets abound. "Generally the quality is high but the food is expensive. Now there is so much food in farmers' markets that it's really cheap. I got these beautiful organic tomatoes for $3 a pound. It's more expensive than a grocery store, but it's a great price for organic tomatoes."