It actually does, if you step back and think about it.
A company offers a product for a price. When you BUY that product, you are saying to the company "the features of this product are worth the price you have set." You are, in effect, voting with your dollars. The company offers a product, you deem it worth the price they set, you buy it.
If you didn't think the phone was worth $600, you shouldn't have bought it. You should have waited until its price was more in line with its features.
Once you HAVE bought a product, that's the end of it. You've said to the company "that product was worth the money I spent, that's why I bought it." From that point on, no one is beholden to ANYONE to keep that price. Why should they be? You've already voted. The fact that it's now $200 cheaper is irrelevant.