When I was growing up, my Nana brought me shopping at Filene's basement in Downtown Boston on Wednesdays, and we bought clothing for all 17 of her grandchildren. She also sewed and created clothing that we loved. This handmade and bargain clothing was passed around and around the family.
Swapping clothes happened because saving money made sense. The happy consequence is that it was one more way for us cousins to stay connected.