Time is really difficult to calculate - do I start from the moment I thought of it? The moment I bought the materials? The second I sat down and started gluing stuff? This becomes a unstable variable really fast - a giant, beautiful lamp may have only taken me 4 minutes to put together, but I've been thinking about it and waiting for the right pieces to come along for 6 years or more! That's either four dollars, or forty thousand dollars :/