and the expense of making a mold is considerable.
To a point but it's all realative...the consistency pays for itself. I have designed many injection molded parts (not audio related) and have had great success. If there is somewhat high volume, it's a no brainer IMO.
That is part of the reason we did a mold for the D1!!!
Though I must say that people really like wood and if done right it yields very nice results.
