If you know what you are doing you can safely buy used photography gear.
I've been buying used cameras, lenses and other photography gear for years.
The last 8 digital cameras I have purchased, were purchased used, online, from private sellers I didn't meet face-to-face: 2 - Nikon D90, 4 - Nikon D300, 2 - Nikon D3 - none with warranty. I still have 2 of the D300 and the 2 - D3. None of the 8 have required any kind of repair.
The only camera repair I have needed in recent years was to a D90 I bought new, but the needed repair wasn't covered by the warranty. A soccer ball ripped a 500 mm lens off the D90 stripping out all the lens mount screws. The D90, on a monopod, also hit the ground destroying the rear LCD. The repair cost me $260.
In the US a camera warranty is usually only good for a year anyway, if you buy new.