Buying A Gently Used Camera?

I want to buy a gently used camera. A really nice one. Like Nikon or Canon. Not a digital, but a single Lens.

Some Like These: http://www.usa.canon.com/...lr_cameras

But I don't want to spend a lot.

That is a good idea
I was thinking about buying the sd4000
from the canon site
all of them are good deals
they will all be in perfect condition

Having owned several cameras over years.
Digital is wonderful total freedom from expensive developing and film costs. The savings will pay for a simple digital in 1- 5 yrs.
Go online to the auction people are practically throwing away their 35mm cameras.
The EOS ELAN 2E is still a great 35mm SLR So is the Elan 7E
Prices drop every year canon 30D or 50D will do great both are digital SLR replacements for the two mentioned above.
Many modern digitals will now take better photos than a 35mm negative.