I had a table at a Catholic conference this spring and had several requests for my Rosary Mystery prints in a small size. So as soon as I got home, I put in an order to the printer (they does amazing work).
The smaller size makes them easier for small hands to manipulate and to hold. A small set would also take up less room if one would want to hang them unobtrusively from a string.
You could also buy a plank of wood, some Modge Podge and Varnish and DIY your own set of Rosary Mysteries on wood if the pre-made one is out of your budget.
You could buy two sets and have a memory game!