I have one AVM Fritz! ISDN PCI card that I bought new in March 2006 for $540, with the intention of putting it in an Asterisk server to connect to an ISDN BRI line. In the end I didn't get the ISDN BRI line, so never used the card, and it is still sealed in it's plastic bag! 
It is in it's original box, with CD, installation guide, and cable to connect to the ISDN port. 

I'm having a clean up, so out it goes :)

Please PM me with offers.

AVM Fritz ISDN PCI Card

AVMFritz ISDN PCI Card - in box