&gt; You also often have injection-molded parts (e.g., the transducer handle itself) that are expensive to produce (the molds for the injection molding machine are done with 3D solid modeling tools, then CNC machined from steel, etc.<p>Just to point out injection molding, 3D solid modelling, and CNC machining don&#x27;t have to be super expensive these days.<p>Large volumes, and especially high end stuff... sure that takes a lot of up-front cost.  But for smaller volumes (eg prototyping, short run) the costs are very reasonable now.<p>It seems due to continuing development of Open Source hardware and software in these fields, which created good virtous cycles for them.  Hopefully this continues... :)<p>Note - saying the above as someone who&#x27;s into 3D solid modelling and CNC machining already.  Haven&#x27;t gotten into injection molding yet, but it&#x27;s on my personal ToDo list for not far off. :D