Erector sets were introduced by the Gilbert company in 1913. As the commercial said, "it's not just a toy, it's a world", and as a child I created my own world out of the pieces, ignoring the schematics that came with the toy. I have been using Erector sets to create lighting for almost 15 years and have installed them in commercial spaces and private homes. Each piece has been unique to its owner so I ththink I am still being true to Alfred Gilbert's vision. Prices vary by design.