I have a bunch of rosaries, and they all came in clunky plastic boxes, which are a pain to carry in your pocket and are always breaking. And I don’t like to carry the rosary loose, where it gets tangled in my pocket knife and other impedementia.
Some visitor to our church lost a leather, 10-sided collapsable coin purse, and I saw it and dimly remembered my grandfather having such a purse for his rosary. After some searching, I found a source on the internet
georgesshoes.com. This is a small company, run by a Catholic family, and they sell their “Round Squeeze Coin Purse” (product ID 22755) for $6.95 plus shipping.