Audio DACs vs Industrial DACs

Hi I am looking to implement a 16 or 18 bit DAC for testing analog inputs of other devices with sample frequency of say 100Hz. When researching appropriate parts there seems to be some very high resolution audio DACs (24 bit) but when it comes to DACs for 'industrial' or consumer electronics they seem to top out around 16 bits, maybe a bit more, and even then they are very expensive compared to the audio DACs.

I imagine an audio DAC has to have good specs, fast (> 20kHz) and very accurate particularly when we talk about 24 bit resolution, so why are they cheap in comparison to an industrial DAC? What can an 'industrial' DAC do better than an audio DAC? For example Wolfson WM8524GEDT/R is maybe $0.70 (24bit stereo) yet almost all 16 bit industrial DACs from MAXIM or Analog Devices are well into the several dollars mark and many are well over $10?

Seems a bit simplistic by why would anybody settle for less than a 24 bit DAC at $0.70?

Thanks for any insights.

The audio DAC is designed for minimum audio AC distortion while the industrial DAC has to meet stringent DC accuracy requirements also that are not important for an AC signal. It's more difficult to get good DC requirements then the AC requirements.