Postcards
Almost everyone has random old postcards lying around in a drawer. A single postcard can sell for $2 or as much as a few hundred dollars, depending on a few factors. According to Warwick & Warwick, the age, rarity, condition, and subject matter all play a role. If the postcard is signed by someone noteworthy, has a message of historical significance, or has a sought-after postage stamp or postal markings, it will bring in more. Some of the more popular collectible postcards can be Art Nouveau and Art Deco style, or feature social history, street scenes, or transportation.