Most of the component cost will be in the etalon but of course the cost of components is only a small part of the cost of running a sustainable business. The PST does seem to have gone up disproportionately though (I think they used to be around half that price new when I bought one second hand for £250 a good few years ago. The pound was much stronger against the dollar back then mind you) Imagine how much the warranty claims to fix all those PST with deteriorating coatings must have cost them though!
Robin