Used tennis balls are 25 cents at the Humane Society Adoption Center at Park Place Mall

Debbie Kornmiller / Arizona Daily Star

Today's tip comes from my colleague Debbie Kornmiller, whose grand-dog recently moved in with her. 

Kingston, her youngest son's nearly year-old shepherd mix, loves tennis balls, and he dirties them up pretty fast.

She was buying them by the case at Costco: 48 balls for $29.99, plus tax, or about 67 cents each. Of course, they were new. 

Then she found this: The Humane Society Adoption Center at Park Place Mall sells used tennis balls for 25 cents each and no tax. Debbie says Kingston doesn't know the difference and she can spend a couple bucks at a time instead of having to fork out $30 when she's out of tennis balls. 

Not only are they good for dogs, but she use them as dryer balls when she dries down comforters, and they work nicely on the feet of walkers. 

The tennis balls are donated to the Humane Society from local tennis facilities. 

If you have tennis balls you'd like to donate, you can drop them by the adoption center during business hours. The adoption center also sells new items such as toys, collars and leashes. It's between the outside doors of Dillards and Sears.