The price of the sound module is not only determined by the hardware costs.
To design the hardware, to develop the firmware for it and the parameterization software require a lot of time.
A Dealer in Germany has to
- Pay 19% tax on each part sold
- Must offer 1 year warranty
- Must pay in advance for electronic assemblies to a recycling system
- who has to offer service
- and many more costs

Without Thomas Benedini, you wouldn't have a decent sound in your truck.
Anyone who buys copied parts shouldn't be surprised that at some point there will be no more developments....