Hi Stefan,
I haven't used it in a long time so I would want to go to my lock up and check it out... Make sure I am not selling you something not good.
It takes NP1 batteries, no doubt they won't take charge any more, it has 4 pin power input as well so no problem...
If it is in good condition and all nice I would say US$6K would be proper I think
It has proper casing and even a crash/splash housing for it, again just have to check out its condition for you
Cheers
Gavin