Since you can examine the camera, it must be a local purchase.
If you can contact the seller if you run into a problem, there should not be too much risk.
If possible, bring you own memory card (probably compact flash card) and take some photos. You can examine them at home on your computer before you buy the camera. You will need a card reader to get them into the computer. Or have your local photo processor service copy them to a CD for you.
I am in the market for a used dslr. Can someone give me some things to do when examining a used dslr?