When choosing wine, a lot of people make their decision based on the price of the wine. To them, the price is indicative of quality, or value. A big issue with trying to find a "good value" bottle of wine is that if you find a very low-priced bottle then the amount of duty and tax that forms part of the price may well be higher than the "wine" portion of the price.
So by choosing a bottle of wine that's just a little more expensive than the "good value" bottle, you may well be getting a lot more "wine" for your money. The recent UK Budget brought a rise in duty on wine and other drinks.
Tax is charged as a percentage of the overall amount, which also means that there was a rise in tax revenue generated per-bottle of wine. This affects alcohol prices in the UK, with the average price of a bottle of wine set to go higher than the current average of £5.03.
This does go some way to qualifying price as an indicator of quality. The higher the price, the more likely it is that the Wine Producer will receive a larger portion of the revenue, but this can become fuzzy when trying to find value in discount deals or bulk purchases.