Why are Lego sets expensive? Wired Science blogger Rhett Allain explains why even if a set had no pieces in it, the set would still cost $6. I'm not sure I would say LEGO blocks are that expensive, but the statement is that they are expensive because they are so well made. Really, this has to at least be partially true. If you take some blocks made in 1970, they still fit with pieces made today. T