How something is made can change the market value if a change in the way something is made allows for an increase in supply. This is heavily dependent on there being a competitive market, however, just as the parent went into great detail over in the comment that came before the one you replied to.
Apple doesn't really operate in a competitive marketplace with most of their products. If I figure out how to manufacture an iPhone for 10% less than Apple, thanks to various protection schemes afforded by law, I cannot reasonably start to sell an iPhone that costs less than Apple charges to try and gain marketshare.
It is true that I can produce a device that has some similarities to the iPhone, but with things like incompatibles that prevent the end user from being able to run their favourite app or integrate with certain cloud services they subscribe to, they are not similar enough for the customer to consider them to be interchangeable. In reality, they would be sold to different markets.
On the flip side, if I manufacture standard screws and figure out how to produce them for 10% less than anyone else who manufactures standard screws, there is a lot of incentive for me to increase supply to attract more customers to my product instead of someone else's. A competitive marketplace is necessary for that to take place.
Given Apple's margins, you probably could sell iPhone for 10% even if having same manufacturing costs.
Sure, Apple built up their brand and their pricing doesn't rely on direct manufacturing costs. And a lot of end-user stuff is the same way. Brand/ecosystem/etc is important. E.g. eating out. Clothes. Food. If you don't go for value brands, you're paying quite a bit for non-manufacturing costs.
