Here's another idea for an exchange that would not cost anything, except postage.
A Why-Did-Buy-This-While-On-Vacation? Exchange.
We all have SOMETHING or items we bought that sure sounded good at the time. And once we get home it just doesn't fit either our body or in our home. It was an impulsive spending What Was I Thinking Moment.
So kind of a "White Vacation Elephant" exchange. Some souvenirs -- such as children -- cannot be included.

Items just need to be in good condition.