(Acura Integra Radio)What is a suggested price on how much i should sell my factory head unit?

I have a 2001 Acura Integra LS radio head unit. I took it right out after i got the car, and I have no need for it. Does anyone know a suggested price to sell it for? I want to get as much money for as i can.|||$25|||I know someone who sold there's on craigslist for $20.00 last year.