Ok, but look at something like the iPod. That strategy makes sense as it is a relatively low cost product. Cost was part of the reason Mac's never got high mark

Ok, but look at something like the iPod. That strategy makes sense as it is a relatively low cost product. Cost was part of the reason Mac's never got high market penetration. The iPhone is very expensive, especially compared with the competition. Offering old models at a lower cost allows people with less money to buy into the ecosystem. This is important when you have a product like the Watch that requires an iPhone first.