The production cost is one of the metrics customers use to decide if a price is fair or not, to them. There are other metrics, like the time that can be saved by using the product (ie. some way to quantify the product "use value"), but the production cost is often quite useful to detect abuses--and boy, aren't there a lot of attempts of such abuses.
only approximately, and only if the consumer really knows the cost.
Think jewlery (like diamonds), or expensive brand name goods like designer clothing. The production cost for those goods is "low", but the charge is in marketing and status symbol representation (which is modified via marketing).
So this looks like a case in point, where having a rough ideas of the production cost (some parts hand-made, made in France/Italy/England, expansive material like quality cashmere etc.) is important.