Are more expensive wines better?

This is a very interesting question. In general, I would say yes and no. However, I'd like to break down the pricing of wine a bit to help make my point more understandable. There are basically five pricing levels for wine, which I have roughly defined in the following illustration.
 I do feel comfortable saying that, as a general rule, moderately priced wines are better than inexpensive wines, and expensive wines are better than Premium-priced wines.
So, what am I saying about Premium-priced wines and the super expensive wines?
Well, starting with the super expensive, the pricing for these wines tends to reflect their demand, which is based on several factors including scores, limited production, availability, and liquidity of the market.
Premium-priced wines, on the other hand, tend to be the worst value play in the world of wine.
Far too many of these wines are not really any better than their moderate-priced brothers.
 They simply reflect several common factors that come into play at these price points, namely: the use of expensive oak barrels to make a "better" wine, lowering yields to increase power and concentration, the costs of marketing of some major brands that play in this group, sheer ego, and the cost of setting up operations in the pricing -regions. 

In time for Valentine's Day Wine and Chocolate

  Wine and chocolate is a mysterious pairing that seems to have starkly different results for different palates. Which, of course, is fine since the only match that is good is the one that works for you. But it does make offering pairing recommendations a bit more difficult than it ought to be!

  There is one standby that works wonders with most chocolate: the sweet red wine Banyuls from Southern France. Banyuls is a small wine-producing region hard up on France's Border with Spain, which may explain why they do such a great job with Grenache, or Garnacha as is called in Spain.

  This tiny appellation is responsible for one of the world’s great gifts to Chocolate lovers: the sweet wines of Banyuls, a great alternative to Port.

  Based on the Grenache grape, Wine seems to have the elusive balance of fruit, sugar, acidity and tannin that makes it chocolate’s perfect partner.

  Similar to Banyuls and other wines of garnache grapes is Port -- in particular, the fruity style of port referred to as Ruby Port, which accounts for most of the branded port wines.

  So, what is it about chocolate that makes it so hard to pair?

  Well, for starters there’s all that sugar and sugar generally requires sugar to achieve a balanced food and wine pairing. In addition, sugar can highlight the acid of a particularly high-acid wine, while at the same time it can make a low-acid wine seem remarkably dull and flat.
One of the keys to pairing food and wines is trying to align the intensities of both. In this case we have both texture and the balance of sweet and bitter to deal with, so you can see how this might end up being a difficult pairing to work with. That’s why going with Banyuls or a similar Grenache wine is such an easy fall back.

  Grenache is well suited to chocolate because of its fruity character, obvious but balanced sweetness, slight tannic edge and overall rich mouthfeel -- four elements that have to be taken into account to make the match work. If you’re not into Grenache, other wines can work with chocolates, but each type of chocolate might require a more specific recommendation.