Sell or donate 21c microphone
Bill Evans occassionally offers to buy back used 21c microphones for $100/ea. If you are interested in selling your 21c, email Bill at ear2sky at oldbird dot org.
You may donate your 21c to Old Bird and receive a $100 tax deductible credit. Email ear2sky at oldbird dot org to make arrangements. Donated mics will be refurbished and put back into service.