You might have to buy the parts of the costume separately maybe, and alter the pieces that aren't quite right to fit the character. I know some costumes i've seen that use that shirt/jacket, only without the white ruffle. Same for the pants. Striped socks...you might be able to find in a halloween store, or a regular clothing store, same with the white gloves, and the boots. the only hiccup I can really see is the hat...and the music box.
For the hat, if you get another hat of that type, you can add the red ribbon and feathers yourself with glue (get a strong type though). Might have to commission the music box....especially if you want a working one. otherwise I'd try making it out of thick cardboard or a lightweight wood, and paint or paste the images to make it look like the box on the side. The handle....hmm....maybe an old bike handle, or bent pvc with chrome paint and a large wood piece for the part you'd actually grab with the hand? It's an idea at least.
