My wife and I love to cook, have discussed opening our own restaurant, have eaten at lots of very expensive "haute cuisine" restaurants and have tasted lots of wines.
Part of the "problem" is that taste is subjective and can be influenced through suggestion. So the atmosphere, the price, the meal pairing can all affect a person's appreciation of the glass.
I remember an episode of Penn & Teller's Bullshit where they had a "water sommelier" at a restaurant who would upsell customers on speciality bottles of water and they were all filled with the same tap water from the same garden hose at the back of the restaurant. The results were fascinating. Subjects swore they tasted different from one another.
The real question, in my opinion, is whether a high-priced bottle is "worth it" by as near-objective standards as possible. In other words, given two bottles of different prices, all else being equal, would the average person prefer the taste of one over the other?
That varies widely from one wine to another. My wife and I have enjoyed a good vintage but we are also perfectly content with a $15 bottle from a local vineyard here in Ontario, which is our "go to." I'm equally partial to a $15 Rothschild Merlot or Pinot Noir and I wonder if the truly exceptional wines that I've tasted at restaurants were more about the environment, the food pairing, the company and the occasion than they were about the flavour in isolation.