I built a 5' by 5'
raised bed from untreated Douglas fir - 2x8's and 4x4's. It has solid construction, carfully squared, with 3" steel lag bolts holding it together. Unfortunately, my landlady does not want it in the spot I built it for. Rather than move it to a shady spot I want to just
sell it for a little more than the cost of materials. It is about 2 feet high, and the legs can be cut to level it where you want it. When you come by to pick it up, take a look at how I used 1'x4's to skirt the inside of my other raised beds; this keeps the soil in the bottom. (The raised beds pictured with tomato plants in them are not for sale.)
http://seattle.craigslist.org/see/grd/755221578.html