I've got my body (300D) and my tammy (17-50mm) as second hand units.
I've just started photography and I'm not how long this hobby can last me. Therefore, I don't see a point in spending so much money on first hand units.
There are some second hand stuff on sale at the forum which are really good price.
And being a very careless person, I don't really have to worry about taking extreme care about my gears. I've brought my cam to beaches, near sea water, getting splash with sand etc, and I don't feel my heart breaking.