I would like to know how hard and how expencive it is to manufacture a USB audio device which has a sampling rate of 32 kHz compared to a device which has 44.1 or 16 kHz sampling frequency. I made a search in google and it looks like very few devices have a sampling frequency of 32 kHz. Is it because it is too expencive to implement or because it would cost the same as 44.1? I`m talking about a simple USB audio input/output device, not some sophisticated USB soundcard.

I rather doubt there would be any special cost considerations, it is highly probably that the chipset manufacturers don't generally bother because there is so little call for that sample rate.

Many USB chips do 32kHz, for example TI's PCM2702. If you are making your own, then this chip would be a good place to start. If you want to buy something - then the specs say that the SoundBlaster Live! 24 external supports 32kHz.

OK, thanks for the advice, everyone.