Pony is right. There have been numerous taste tests where the same wine is include more than once at different prices. When the tasters see the prices during the tasting they always rate the (same) wine higher when it is listed at $50 than they do when it is listed at $15. Same wine.
This is not only true about wine. With virtually every consumer product we make they same judgements. Price, to most people, is an indicator of quality. It happens in cars, restaurants, clothes, just about anything you can name. Why should wine be any different?
This is a slightly but notably different variation of what pony was talking about. Pony said that the average person can't distinguish a cheap bottle from a good bottle. For the average consumer, I wouldn't contend that. That however does not mean that there isn't a difference- just that you need experience and desire to detect and appreciate the differences.
Now what you're saying is that the consumer is influenced by price, and price point impacts perceived quality. I can't argue that either. But that also does not conflict with the fact that better wines, in general, cost more. Nor does in conflict with the fact that there is in general an increase in value to coincide with an increase in price.