Instructions
Go to your local library, which will likely have a shelf of antiques books, and look for a recent general price guide, such as Kovel's or Warman's. In the U.S., antiques and collectibles price guides are updated by publishers every year. The guide will be divided into sections on furniture, collectibles, paintings, jewelry and other categories, and usually each section is further divided into smaller subcategories. It will also have an extensive index.
Consult the index or go straight to the appropriate category if you have a clear idea of what your antique is. If, on the other hand, you have only a vague sense of how to describe it, you will have to patiently thumb through a broad section until you come across something that looks similar. Fortunately, these guides are very well illustrated. If you can't find your particular antique, try another guide.
Read the entry carefully and make notes. The information that you garner here will be useful should you wish to conduct further research. See how well the description matches your particular item. It might be that, although theoretically similar, the item listed is in much better condition than yours or has additional features, such as its original packaging. In that case, your antique will be worth less. Lastly, take a look at the price guide value. This will be expressed as a broad estimate -- perhaps $20 to $40 for a less valuable item, or $300 to $400 for something more expensive. For a realistic estimate of your antique's value, it is best to go by the lower figure, and then deduct a little more depending on damage. How much to deduct depends upon the kind of item. A toy with pristine packaging can be worth twice as much as one without. A small chip can devastate the value of a piece of glass because it is impossible to repair except by grinding down the surrounding area. Because it can be restored relatively easily, a similarly sized chip might knock only 10 percent off the value of a piece of porcelain, depending on where it is located; if it is tucked down near the base, some collectors might choose to overlook it. An old piece of silver might be in otherwise good condition, but if its hallmarks are so rubbed that they are illegible, then serious collectors will have no interest in it; it will only be worth its value in scrap.