Interesting analysis. Two comments:
(1) Within a product, does it make sense that pricing has to converge near zero? Adding a notebook analysis may illustrate that this is not always the case.
(2) It may be interesting to look at the interaction between products, rather than focusing within each product and answering what drives the purchasing decision for each product. For example - it seems as though the iPod would fit nicely into the "Insert iPad Mini Here" triangle; however, are the purchasing drivers for the iPad and iPod congruent? Would one trade up or trade down between the iPod and iPad purely on price?
