Cast and extruded acrylics are available in a variety of sizes and some colors. Look at Ed Davidson's YoYos to see some of the opportunities available (Ed is known as YoYo Spin). Ed did a DVD on one piece yoyos that show cases his use of purchased acrylics.
Tell us more about the applications because there are lots of differnt products for different uses, and some work better than others -- e.g. cast vs extruded acrylics.