Apple product prices don't drop because they have much greater longevity than other products, they don't have the competition, and Apple don't release several revisions per year (whereas others use all sorts of silly names to identify their mass of products such as HP g6-1204sa).
Apple hasn't got a valid reason for such a huge markup on upgradeables like RAM and SSDs. It's not as if they mass-ordered them years ago when prices were huge and keep stock for ages.
You now all of this for sure and have proof? Some companies do purchase the products in advance. Just because the release cycles are farther apart speaks nothing to a products longevity. I will agree that their products hold value better in the long run than others, but that speaks nothing to longevity. Apple does release revisions during the cycle as well, they don't really differentiate them though, this is how we have issues with taking firmware updates and support of SATA 3 appears on the ODD drive that didn't exist in the early releases.