Now we are getting to the real reason why you want to clear out that basement, it is so you can put your motorcycles down there!
To allay your fears, if an old camera isn't worth something yet, it never will be. By old, I mean pre WWII.
Just go through the cameras a little at a time and use Google and ebay to determine if they are worth anything. If you have a question about a particular item, ask here. It shouldn't take you that much time if you are efficient about it (i.e. don't fondle everything!). Keep all the film holders, lenses and any cameras you recognize right off the bat. You can throw things right in the trash if they are trashed, like old small bellows cameras that are ruined, and just get rid of any large strobe equipment. It won't work and isn't worth fixing. Light stands can be sold though. Bulky things like backgrounds can probably be trashed if they are not perfect.