I worked in radio...and play on Ebay occasionally. Just checked and the average sale price seems to be around $30 - $40 per show when checking December 2006 completed sales.
Some are more rare than others, and it appears the older the better. I'd suggest list them on Ebay and set a reserve slightly lower, say $25 per show. Good luck!
Thanks BB, actually I needed a price for the insurance company, they got a little soaked...
Oh, well in that case, tell them you discussed their value with a radio station consultant (me), and that they were worth approximately $70 each, as they were in mint condition and had never been played...