All I can comment on is the price. $16,500 is very close to median. The low book is just under $14K and the high is just over $19K for this car in Excellent cond.
This is the best I can do.
Hope this helps.... here is the link to NADA website...
http://www.kbb.com/
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William
76 240D - 550K miles
78 300D - 200K+ miles