PHYSICAL CONDITION Older cameras have many potential issues. A partial list of the most common defects would include: deteriorating light seals and/or mirror foam, internal dust or dirt on the prism or focusing screen, sluggish mirror return, inaccurate shutter speeds, dead or inaccurate light meter, shorted electronics, stripped film advance gears. The charges to fix ANY of these problems usually starts about $75.00 and escalates upwards from there and that is just for the labor. If parts are required most often the camera cannot be repaired as parts have not been available for a decade. It is a wonderful thing that these cameras were so well made that if handled properly they will last another generation or more. It is important that when you buy a used camera you have an INSPECTION PERIOD and a total RIGHT OF RETURN. If not you may get lucky and get a camera with no issues (in my experience that would be VERY lucky) more likely you will have a servicing bill that is equal to or greater than the cost of the camera.
COSMETIC CONDITION The cosmetic condition of the camera is the most important clue to its prior handling. Some examples: If the camera is dusty you should expect that the same is true internally, the camera likely needs a CLA (cleaning, lubrication & adjustment). If the camera has dents & dings it has been handled harshly and all functions are suspect. If heavy brassing (finish worn through) is evident then heavy use is indicated and shutter and mirror functions need careful attention. On the flip side, if the camera is beautiful on the outside it has been treated carefully and may have seen only light use. In this case only normal maintence may be required. Since there is no accurate way to describe the cosmetic condition of a camera, and no two people would agree anyway the photos are the final source of information. REPEAT- Carefully inspect the photos of the camera for clues to its previous usage and handling. If the photos are so poor that you cannot determine the details that may be a sign that the cosmetic condition is poor. BE WARY if the photos are very dark, small or out of focus.
LIGHT SEALS & MIRROR FOAM These are internal rubber pieces that, like the oil in your car, need periodic replacement. Varying with conditions they need to be replaced every 8-12 years. Like lubrication you cannot tell from the cameras cosmetic condition anything about the light seals and foam as time is the biggest determining factor, not use or handling. This is the most common flaw and the easiest to correct though the standard charges are still in the $75.00 + range.
BRASSING This is where the finish is worn away to the point that you can see the underlying brass. The degree of brassing is another clue to the use and care of the camera. Though common on painted finishes brassing can be avoided by preventive measures such as leather washers around the eyelets. If you see brassing to the point where the metal itself is worn AVOID that camera as the structral integrity of the casing has been compromised. Light, mild brassing on painted finishes is nothing to be afraid of as even limited, careful use can produce this.
CANON SQUEAL This is a lubrication (lack of) condition. The Canon A series cameras (AE-1, A-1, AE-1 Program) require periodic lubrication of the mirror return mechanism every 10-15 years. The first sign that lube is needed is a squeak or squeal that the camera makes from time to time when the shutter is fired. The next sign is when you hear the squeak every time you fire the shutter, by then the mirror may be returning slowly and you can not take two pictures in rapid succession. The final phase is total mirror lockup.
CAUTION SIGNS 1. Any form of sale where the camera is untested. As a tested & working camera is worth substantially more than an untested one and it is not hard to test that it is taking good pictures why would the seller not test the camera before sale? There are many excuses for not testing ie: "estate sale", "no battery", "do not know about cameras", "worked last time I used it", "was my fathers" etc. All these reasons lead down the same path, the seller is UNWILLING TO COMMIT THAT THE CAMERA WORKS. Much of the time that is because it doesn't.