There aren't many of these ingame, so it wont go cheap, however I know the featured auction had them for 245k crowns. I wont be checking this thread often since my browser is playing up, please send an offer ingame through mail.

Coal: Looking for 300ce each.

IGN: Joshn, I very rarely check my Spiral-Wiki alt.

Edit: Let this die, combining it with my old thread:
http://forums.spiralknights.com/en/node/34243#comment-210690