I probably won't get into the film scenario- just don't want to sell a duff camera
I sell a *lot* of film cameras for the charity shop I volunteer in. I don't put a roll of film through any of them.
Battery in, open the back door. Check around the edges looking at the seals. Take a photo of it. If they look good, say so in your description. If they look bad, say so in the description.
Examine the lens if you have one for fungus/dust. State your findings in the description. (i.e. lens looks clean/has fungus/a little dust)
With the back open, set the shutter speed to 2 seconds and fire it. Watch the shutter open and close. Test again with it set to bulb to make sure it opens and closes when you release the shutter. Try again at 1/30 and 1/250. Make sure the shutter opens and closes at those different speeds. As long as they're different, you're probably ok. Those Canon cameras were well built.
You don't say whether you have a lens, but if you do, set the aperture to the extremes (f/2.8 & f/16 for example) and do test bulb shots to see if the aperture is open at the widest and stopped down for the narrowest.
Set it to whatever automatic mode is available, and take photos at different scenes (one out the window and one inside in gloom) you should hear the different shutter speeds to confirm the meter and auto functions are working. Check the aperture is opening/closing too if you can.
As you wind on after each shot, make sure the winding handle is turning the film take up spool inside the camera.
Check the battery compartment for corrosion. State the condition in your description.
If everything works ok, I'd sell it as it is. You can probably get £60-150 on eBay depending on what lens it has(nt) got, and the condition/your optimism. Take a photo of the serial number before you post it.
If anything doesn't work, sell it on eBay with a description of what's not working, and accept the price drop.
Alternatively, send it to West Yorkshire Cameras or Ffordes. They will test it and pay you what it's worth although you will get less than on eBay - typically 30-50%. If you're feeling really cheeky, just ask them to send it back knowing it's been tested.
Finally, you could sell it in the classifieds here, but if you do, I'd add everything you'd put on an eBay listing.
By not putting film through, you're taking a risk, but in my experience, there's quite a bit you can check without film in it. The cameras I see, generally either have many problems, or none at all. I did have an issue with a Canon FD camera recently where the shutter wouldn't fire. A quick google, removal of the baseplate, poke with a screwdriver, and a dozen test firings later and it was fine. Buying a roll of film, & getting it dev/scanned won't prove much more than not doing it and would probably dent the profits as well as being a hassle if you're not interested in pursuing film photography.
