Find out in the front HOW old it is and then try and workout how much you would pay for it? Maybe ask a libarian. He/she would most-likely know. If not then have a wild guess.
Google, or a book made especially about old coins.
Blue Book of Gun Values
Abebooks.com is a good place to start.
The best place to find the value of your old car is to get the Kelley Blue Book value. You will find this at www.kbb.com, and enter the car's information on the website in order to determine the car's value.
Look up "Blue book of airguns 8 edition."
Go to a book store or Library and find a book called "Blue Book of Airguns 10 edition." In there you will find on page 634 the set values for the webley Junior.
A car's value depends on the year, make, and model as well as the amount of wear and tear on it. Blue Book should give you a base amount to start with.
One can find the Kelley Blue Book value of a car directly from the Kelley Blue Book website. One only needs to put in information on a car in order to get the value.
IN a libary
ebay?
Blue book online.
To find the value of a used car there is a book you can use for your research. The book is called The Blue Book. I have used it before and found it to be quite reliable.