If you’re looking for information about how much your comics are worth, nothing beats actual sales data. While I recommend serious collectors, investors, and those with considerable comics they are looking for value to pick up a copy of the Overstreet Comic Book Price Guide, there are a few other places to look for actual sales data, and this the Sparkle City comic book values page is another one. I especially appreciate Sparkle City’s comment:

If you’re looking to see what the current market is like on certain books, nothing beats actual sales data. Comic Book Price Guides are great tools for collectors, but they are just as the name implies; guides. Often comic books only sell for a percentage of a stated guide value or in the case of high grade or ultra scarce books can sell for over guide value. Nothing beats honest empirical data when trying to get honest comic book values!

Check out their actual sales tool here: Sparkle City Comic Book Values (complete with scans!)