Reddit mentions of The Ultimate Guide to Vintage Star Wars Action Figures, 1977-1985

value is really in the eye of the buyer. what they are willing to pay. I use ebay as a good guide, but most thing are overpriced especially when you consider shipping, as the price may be great but then you'll see $40 for shipping on one action figure. here are a few guides that have used in the past:
http://smile.amazon.com/Ultimate-Vintage-Action-Figures-1977-1985/dp/1440240590/ref=sr_1_1?ie=UTF8&qid=1462312323&sr=8-1&keywords=star+wars+price+guide

http://smile.amazon.com/Star-Wars-Ultimate-Action-Collection/dp/1452111308/ref=sr_1_2?ie=UTF8&qid=1462312323&sr=8-2&keywords=star+wars+price+guide

http://smile.amazon.com/Official-Price-Guide-Star-Memorabilia/dp/0375720758/ref=sr_1_3?ie=UTF8&qid=1462312323&sr=8-3&keywords=star+wars+price+guide

http://smile.amazon.com/Pickers-Pocket-Guide-Star-Antiques/dp/1440245827/ref=sr_1_5?ie=UTF8&qid=1462312323&sr=8-5&keywords=star+wars+price+guide


keep in mind also most of these came out before the force awakens and a resurgence in the force, so values may be under-priced.
also I have several of these books if you need me to look up items, I would be more than happy to.