Many people enjoy collecting vintage postcards both for their creativity and the nostalgia they often induce. Postcards began appearing shortly before the 1900s, and were very popular through the first half of the 20th century. A vintage postcard's price may vary dramatically from a few cents to even thousands of dollars. Many factors determine a postcard's price, including age, condition, topic and rarity. Pricing a postcard accurately takes careful examination and patience to ensure all factors are considered.
Divide postcards in terms of condition. Set aside any damaged, creased or dirty cards into one pile. They are less valuable and will not fetch as high a price. Those that are pristine or in mint condition should go into another pile.
Divide the mint condition cards in terms of their date. This can be tricky, as postcards may sometimes be purchased, stored then used months or years later. You'll need to look at three factors: the mailing date, the date written on the card, and any dates potentially on the postcard itself such as next to an artist's signature. Use the earliest date. If you cannot find a date, either consult a postcard encyclopedia or, if the artwork is classic of a certain time period, research artists or card makers to see if you can identify its year.
Organize these cards by their date, placing the earliest at the bottom of the stack and the latest at the top.
Examine each postcard for its topic. Cards such as Christmas and birthday cards are quite common. Unusual topics, such as fantasy, ethnic cards and some political cards, are rarer and worth more.
Pick out any Real Photo postcards. These are cards that were actually made with a camera then developed in a dark room. There are many black and white postcards, but RP cards will often have a sepia tone. Captions will be in white. Some of them are one of a kind. These are likely your most valuable cards.
Price RP, one of a kind and unusual cards first. You may want to use a reference book or take them to an appraiser if you're certain you have very rare and valuable cards. Their prices may range from $10 or $20 to $100.
Mark the more common cards at prices relative to your rarer cards. For example, a Halloween card may be priced at $20, but a more common Christmas card by the same publisher may only be worth $5.
Price the damaged, dirty or creased cards last. Depending on their condition, they may be worth 10 cents to a dollar, even if they are potentially uncommon. The only exception is RP cards, which may still bring a few dollars despite their condition.
Look for cards marked by a post office that no longer exists. These sometimes have value to certain postcard collectors. To determine this feature, look up the ZIP code in a post office directory. If there is no office there, then you have a discontinued post office cancel, or a DPO. Also note how long the post office was in business. In general, the shorter life span, the greater the value of the card.
Examine postcards you feel might be real photos carefully. Many fakes and knock-offs exist. One sign is the presence of dots or pixels in the photo. These did not exist on the originals. Also, RP cards are often printed on photographic paper, and you can often find its seal on the back of the card. Study the caption as well. Neat captions often indicate that the card is mass-produced, though it still may be authentic. Hand-written captions occur on one of a kind postcards.