$10 of soft hide, and $5 of lacing, and an exacto knife, and you can make a gather-top sack... one whch opens flat.
Add a $3 bottle of leather paint, and add his name and/or a design.
Edit: the pattern is simple: cut a circle, about 18" (45cm) across. put a series of holes, each about 1/5" diameter (5mm), 1" (2.5cm) in from the edge, about 2" apart. run the lace through said holes, tie into loop. With the lacing almost completely used, it should be lying flat. When closed, the lacing wraps around to hold it securely.