Calculating only the polisher's salary as a base of camera costs (I guess, you wanted to type 1500, not 150?) - now that is a weird thing to say. On the other side: How big the surprise would have been if Leica made a camera which is not the most expensive in it's class? As long as they have customers to pay, all other manufacturers could remain envy.
I believe the intention there was to estimate how the base cost translates into retail cost. Normally this is used on part costs, as opposed to the transformation cost applied to those parts, but similar sort of thing. It is like when people say "but that bit of plastic only costs cents, why do we have to pay dollars/euros for it?" Well, the plastic may cost cents in material cost only, but transforming it into a product and selling is not zero cost... so back to the polisher, his basic wages will factor into the product cost, but it isn't a direct relationship and due to other factors (like other overheads mentioned already) that contribution will be some higher cost at the end product you see in a shop.