Is there really a big difference in taste between cheap and expensive wine?
Sometimes yes, sometimes no. It's foolish to assume that spending more on a bottle will always man greater pleasure.
The fact that you feel compelled to ask suggests to me that you are skeptical about the correlation between price and quality, and I salute you for it. To some extent, very fine wines do cost more to produce. They tend to be made from vines that are laboriously pruned to yield fewer but more concentrated grapes. Less fruit per acre means higher cost per bottle. And those grapes are often hand-sorted to ensure that only the best berries make it into the fermenting vat. They may also spend extended time in oak barrels, which adds considerably to production costs.
But supply and demand can figure heavily into the equation, too. The rarer the wine, the more expensive it tends to be – regardless of quality, which can be very subjective. Is a $100 bottle 10 times "better" than one that sells for $10? It's a judgment call, and I think most people would be hard-pressed to answer yes.
Often, trained tasters will in fact prefer a less expensive wine to a trophy label, especially when they taste "blind" (without the advantage of peeking at the label or sticker price). I recently sampled a $115 California cabernet sauvignon in the company of several veteran wine writers, all of whom, including me, expressed shock at the price. Many awarded a higher score at the same tasting to a lovely $22 red Bordeaux, also made primarily with cabernet sauvignon.
And style preferences can play heavily into one's personal assessment, which is all that counts in the end. Grand cru Burgundies can easily exceed the $100 mark, not because they're always sublime but mainly because they come from storied vineyards and are produced in tiny quantities. But if your tastes run more toward full-bodied reds, such as Australian shiraz, chances are you will find more bang for your buck at $15 or $20. My advice? Drink the wine, not the label.