Factory repair manuals; What are they worth?

[Jim Dupree]

Hi all,
I have a chance to buy several sets of Audi factory manuals but I am wondering what they may be worth. These are the multiple booklets in gray covers . there are typically 12 booklets per set and they cover a chassis group per set. There is a set for the 92-97 100/S4, A6/S6 (the set I want), 93-95 90, 97-on A4, 97-on A8, 98-on A6, 95-98 Cabriolet. There are also several electrical diagram book for various models from about 1989 to 1991. There are some other booklets in the mix but I don't recall what the cover. 
This is an all or nothing deal I have been offered But I don't have a need (or desire) for all of these so If anyone has an idea of what I could realistically sell these for I can decide if I can take the deal. These sets ran about $300 each new and the diagram book were around $30 new but with CD's available cheaper the value of these must have dropped off some. I have a couple of the CD's and they are nice since they are small and cheap but they are hard to take over and set of the fender while I work on my car so I really want the paper books.
Any thoughts on values would be helpful.
If I buy these I will of course post them for sale on the marketplace first so you will all have the first shot at them.
There is also a chance I can get some older Bentley manuals.
Thanks
Jim Dupree
jdupree914 at sbcglobal.net