Is there an easy way to look up the value of a used car?

I forgot to write down the kind of van but I think it is a Dodge Caravan %26amp; maybe a grand caravan but it has 100,000 miles %26amp; is a 2006. I want to find out if they are asking a fair price. How can I easily do that? Thank you.|||=== the Kelly Blue Book is about close ==== the real info is at the sales sites on the NET ... if you google/search %26lt; used cars for sale Ur city UR state %26gt; in the search bar === you will get a true street value for a car ...... suggest you do %26lt;used cars for sale Houston Texas%26gt; and this city has lots of cars for sale and the prices are competitive.....|||The "Blue Book" (available in libraries, at auto parts dealers, or perhaps online) lists true values based on mileage and year, make and model.|||Kelley Blue Book website.|||go to www.kbb.com (kelly blue book) and you will find out everything you want to know.|||Kbb or nada online....|||Kelley Blue Book online.