I'm selling a black Baby Bjorn since my kids are turning one and are too heavy for it. Was used occasionally during the last year but in excellent condition. It's the traditional model:
http://www.amazon.com/BABYBJORN-Baby-Carrier-Original-Cotton/dp/B0009JOSNM
$25 plus shipping (price is negotiable!)
Happy to answer any other questions!
Hoping I can pass this along to another HB mama!