The circuit is not all that complex. It's got about 40 components. Still, given the extremely small quantities I would be purchasing the parts in, as well as the hand assembly, $50 would be an impractical. I would lose money on every one made. I think the most likely price would be around $100.

at some point ,the sound improvement from a digital output board + DAC isn't justified by the cost (e.g. the money could be put towards better spedakers), but oh well. :-)

Remember, the better your speakers and other equipment, the more you are going to notice any deficiencies in the Empeg's D/A converter. Many people spend much more than $100 on cables. Unlike these cables, the digital output will make a real difference in the sound, provided you are feeding it into a good quality D/A converter.

Stu