If you think the price is good then don't be afraid of buying used equipment. With camera bodies do the black test with cover but also cover up the viewing lens that you look through as it contributes a LOT of light leakage and some will show a gradient in the image. Try throwing any DSLR into AV mode with the cap in place and then move your thumb over the lens to see how much the exposure time will change.
When you go to look it over you also want to look over the sensor and mirror for scratches. Take a hand lens and a small flashlight with you to have a directional lightsource in order to do this.
The shutter count is of more use as a haggling tactic in the end. Replacement shutter assemblies can be put into most cameras for a few hundred dollars. This effectively replaces most moving parts of the camera and gives you in essence a rebuild with full shutter life expectancy. Just make sure that if the count is over 100,000 that the price is dropped by this cost to keep your cost of buying used at a low enough percentage of new to retain the savings.
One thing that makes me walk away is lots of dings and scratches on the body. If the body has had enough impacts over time it can cause connectors and electronics to fail. If the body is clean, not banged up, and looks like it has been cared for then I have no real reservations in most cases.