That's a false dichotomy. A good's price is tied to how much you'll pay and how much it costs. If an iPhone cost $200 more to make, it'd be a good bet that it wouldn't sell for the same price.
Not really. The price is a function of the value to the buyer, which drives demand and is independent of manufacturing cost. Above a certain price I just won't find an iPhone to be providing value, so demand will drop. Apple has some room to cover costs with price increases, but it's limited.
If the good costs more to make than the buyer is willing to pay then there is no price because there is no sale, so clearly price depends on cost. Functions can have more than one input.