provided you look after them.

For example if you're in the rain, keep the camera covered over when your not shooting. If it gets some rain on it wipe it off with a cloth. A hankerchief is fine.

In dusty conditions, just make sure you you usr your body to shield the camea from the dust when changing film or lenses, or use your camera bag to do these.

Also after use, make sure you clean your camera. Use a blower brush or can of compressed air to clean out the mirror box and the film chamber. Use a lens cleaning cloth to keep the lens and viewfinder eyepiece clean.

I've used EOS cameras for 12 years, first an EOS5 and now an EOS3 and nrver had any problems. I even managed todrop the EOS5 at one point, putting a small crack in the body. It still worked perfectly.

On the lens versus body question; what would a better body allow you to that you can't do now? If there is something important then get the body. If not get the lens.

Simon