All I did was flip terracotta pots upside down and add a piece of old wood between. Bigger pots on the bottom, ascending in size for each shelf towards the top. We store grilling supplies in the pails, gardening supplies and wood. My favorite part is how we use the shelves to display and contain treasures from nature. Rocks, pinecones, shells, etc. I'm sure this will come even more handy when our little one is big enough to be interested in nature collections. A great way to encourage collections without having them overtake the house.
Cost: I did have to buy the big terracotta pots, so I think I spent around $20.