My co-worker and I built these planters from pallets that we had lying around at work. The only expense we had was the Kreg Jig I purchased (and love). It took us about 5 hours to put them together, including the time it took to cut the lumber to size. Then we used Thompson's water seal and stapled commercial grade landscaping cloth inside the planter. We made them for work and hope they will just naturally age. This was an easy project and we will definitely make more of these.
We had leftover screws, landscaping fabric and water seal from other projects.