- Find the serial number on the guitar. Although using serial numbers is by no means an exact science due to inconsistent labeling, they can give you a general idea of the instrument's age. Check either side of the headstock or the back of the guitar where the neck and body are joined.
- Look at the first two digits of the serial number. Generally, 1980s Fender serial numbers have an "E" at the beginning. The number after the letter can be used to determine the date. A larger number denotes a later date. For example, a guitar that says "E2" at the beginning of the serial number will have been made in either 1982 or 1983. If your serial number starts with a "V," it's probably from the U.S. Vintage series. Use an online serial-number decoder such as guitardaterproject.org.
- Examine your guitar for any damage, including chipped paintwork and any dents or cracks in the body or neck. Ideally, you will not be able to find anything wrong, but a guitar from the 1980s is likely to have at least superficial damage. The more damage the guitar has, the less its value.
- Determine the model of guitar. Fender Stratocasters have two cutaways on the body at the side of the neck, creating what looks like two horns bending slightly inward. A Telecaster has one cutaway. Search the Internet or use a book such as Gruhn's Guide to Vintage Guitars to determine the model. Stratocasters made in 1980 should be colored Candy Apple Red, Lake Placid Blue or Arctic White. If your Stratocaster has a reversed headstock, it may be a Jimi Hendrix-inspired model. Reversed headstocks have machine heads pointing downward when the instrument is being played.
- Use a book such as the Vintage Guitar Price Guide to determine approximate value of your instrument. Search websites for your instrument to see the selling prices. You may not get the same amount for your instrument, but you'll get a general idea of its value.
- Find a local Fender dealer for a professional appraisal. Use the Dealer Locator on Fender's website to find a nearby outlet. They'll appraise the instrument and provide an opinion on the value of your instrument
Source : http://www.ehow.com/how_8532979_appraise-1980s-fender-guitar.html#ixzz1PD06a4D3