Still, if you need a work truck, buying a used one thats never been used for anything other than commuting is probably a good move - its what Id probably do.
I bought my pick-up used. A 1998 Chevy Silverado Z-71 3-door. Came off a lease that I figure was used by a project manager or something. Judging from the marks in the back seat where his file storage was.
I really wasn't even seriously looking, it was just something in the back of my mind. Anyway I was on lunch one day, and drove by a tent sale at the mall. Kinda cruised around looking, and right before I left the parking lot, something in the corner of my eye grabbed my attention.
So I got out and took a look. It had the right color (dark green metallic), bedliner, rail guards, leather seats, Tape and CD, full gauges. The only drawback was the automatic (I prefer manuals). Still, I ended up buying it.
I haven't taken it off road much, but the 4x4 comes in real handy in the winter. And ball haul'n through 12 inches of fresh powder is a blast, if you can find some road/parking lots before the plows and other traffic ruin it.
All in all I'm pleased with the used purchase. Haven't had a problem with it other than basic maintenance and wear and tear issues. (Filling the tank is another issue) Nothing wrong with buying used if you take the time (or get lucky like I did) and look around.