Cameras have been around since the 1830s, although most of the models most people know about appeared in the 20th and 21st centuries. Finding an old camera in your attic may make you think it can bring you a small fortune, and in some rare circumstances, it can. It depends usually on the brand of camera you have, what the original quality was and how it has held up, and the demand for such cameras. You can price an old camera at anything you want, but unless you have something special, do not expect a large windfall profit.
By far the most abundant cameras since George Eastman's company, Eastman Kodak, introduced the Brownie in 1900, are consumer-level cameras. These range in quality from fairly good all the way down to downright terrible. For example, Kodak and other companies produced a variety of cameras in the 1930s that look like they should be worth a lot of money right now. They have bellows, an aperture ring, a shutter speed control and use medium-format film. Unfortunately, many, many of these were produced, so even today they are quite abundant. Kodak also had an unfortunate habit of making cameras that took specific and odd film sizes such as 616 and 620. While the film itself is standard 120, the spools are different. Since Kodak and other companies stopped making these types of film many years ago, these and many other consumer-level cameras do not work without modifying the film. If they cannot get the film, most people looking at old cameras will pass by the ones that make it difficult to use them. This problem even extends into the 1990s with such cameras introduced previously to take disc film or 110 film. As digital cameras claimed the market, most film manufacturers still left in business tend to stick with what still has a market, films such as 35 mm, 120 and 220. Do not expect most consumer-level cameras to fetch more than $10 to $20.
You will have better luck if you have an old camera classified as a professional camera in your closet. For example, if you find a collectible camera with a name like Hasselblad, Nikon, Rolleiflex, Leica, Mamiya, Bronica or Contax, you may expect to bring in more money, usually in the hundreds of dollars. For truly sought-after cameras such as the Rolleiflex and Leica, you still may expect to get more than $1,000, if they cameras are in good shape and light tight with no lens problems. The standard medium-format workhorse, the Hasselblad 500C or 500CM may have cost around $3,000 new, but today even in the best of shape, you may only get a couple of hundred dollars for each. Even though Nikon started the 35 mm system camera revolution in 1959, even the earliest Nikon single-lens reflex cameras only fetch a few hundred dollars.
Technically, antique cameras were made more than 50 years ago, but in this case, antique cameras generally come from the 19th or early 20th century. Condition is everything with these kinds of cameras. If you have a view camera, the type that produces 4-by-5, 5-by-7 or 8-by-10 single negatives, the bellows may have rotted by now and have light leaks. They still will sell for more than $500, but if you have one that essentially looks like you just walked into a camera store in 1890 and bought it new, you can expect in the low thousands. These types of cameras were generally used by professionals.
Instant cameras, made primarily by Polaroid and, for a short time, Kodak, have little value because the film has become unavailable. Some of the older Polaroid models with bellows from the 1950s and 1960s may bring a price of $50 to $100 as collector's items, but the more common and newer models rarely sell for more than $20. The One Step model and the Swinger may have nostalgic value to some people, bringing in up to $30, but that's about the limit. Kodak instant cameras, despite their limited availability, rarely go for even $5 to $10.