The "guru" of kit collecting is John W. Burns. For years he has been compiling and publishing his "Collectors Value Guide for Scale Model Plastic Kits" His address is: 3213 Hardy Drive, Edmond, OK, 73013. He also does the Kit Collectors Clearinghouse, which is a bi-monthly newsletter. See some info at: http://www.geocities.com/SunsetStrip/1805/kcc.jpg . HTH.
Jim Whitley