Can I get an appraisal for an Nikon AF Nikkor 20mm 2.8 D lens?

My boss is having me research how much this lens goes for, I've looked over at keh.com and can't really seem to navigate my way around getting an appraisal for this specific lens. I have no experience using cameras so I don't really know all the camera vernacular. Not sure how strict the condition standards are for lenses, but it seems to be in good condition with no major scratches or dings.

About $600

http://www.amazon.com/...B00005LEOC

http://www.bhphotovideo.com/...le_AF.html

http://www.google.com/...f&bav=on.2, or.r_gc.r_pw.&fp=4ccf944683288bc4&biw=1024&bih=578