The production costs of an item shouldn't actually matter at all to your end. All that matters to you is the use / enjoyment you get out of the product, and whether the price fits that value.
Is the PS3 or Xbox360 worth paying more for, simply because they cost more to produce? What if the Wii is the most used console in the house? What if a $600 PC offers more / better features than the $800-to-produce (at the time) PS3?
The "production costs matter" argument can apply to videogames themselves, of course. Do you think GTA4 is worth paying more for because it cost so much to produce? Are 2D games like New Super Mario Bros. Wii not worth paying full price for because they cost less to make, even if the end product turns out more enjoyable than big-budget titles?
Companies like Apple or Nintendo are able to charge more because they create value out of ideas that their competition either hasn't thought of, or can't understand. As a result, these companies also happen to be the ones pushing creativity / innovation, so I'm glad they're as successful as they are.
Take your mp4 example: you say there is a product much better than the iPod, but what does that mean? It may have more features, but is it as user-friendly, as stylish, or as "fun?" Really, all that matters is whether the product itself is worth the price or not. You should be focusing on the differentiating features, the opportunity costs, stuff that actually affects the buyer (you), not the production costs.
It's not as if Sony owes you a price cut each time they reduce the costs of its system. While we're at it, why do you expect the price of Nintendo games to go down over time? If the game is good enough to stand the test of time, the price shouldn't be dropping.
