Recently, I did something that I have done exceedingly rarely in my wine-buying life: I sold some wine. Now for some wine drinkers, buying and selling wine is normal. A lot of Bordeaux buyers engage in this as a matter of course.

But that's never been the way for me. Over decades I've lovingly—and occasionally expensively—built a wine collection that has given me daily satisfaction. Until now, it never occurred to me to sell. Quite the opposite: It always occurred to me to buy. I've always loved buying wine. Selling them was unthinkable. I wanted to marry these wines, not just have a little fling, only to toss them aside for a new fancy.

So why then am I now selling wine? It's not because of the money, although that's always nice to have. Like everyone else, I can always use a little spare change.

I should mention that the wines I sold were among the most expensive in my cellar, rarities that truthfully I could barely afford to buy, but I could not bring myself to resist. They were among the greatest wines in my cellar.

So why did I sell? The answer lies in a single word: surprise.

Perhaps it's a stage in a long wine life, but what I now seek from wine, more than anything else, is the element of surprise. The novelist Henry James captured this perfectly: "There are two kinds of taste, the taste for emotions of surprise and the taste for emotions of recognition."

Today, more than ever before, I find myself with an almost urgent taste for emotions of surprise. Expensive wines rarely offer that element of surprise for me anymore.

Mind you, I'm not saying that expensive wines aren't great. Or that they're not wonderful. Or that they're not worth the money. But if you've been around the wine block a few times, they rarely surprise. You have a good idea of just what expensive wines are likely to deliver. Can they be thrilling? You bet. Are they intensely enjoyable? No doubt. But are you surprised? I doubt it.

Expensive wines, almost by definition, are known entities. They come from famous places, famous vineyards, famous producers. They are sanctified by tradition and endorsed by generations of wine lovers. They repeat their greatness over many vintages. (I'm speaking here, of course, of true classics, rather than one or another cult wine that skitters into the price stratosphere because of points awarded by one or another wine critic. Revealingly, there's no element of surprise with these wines. They're utterly predictable.)

Expensive wines rarely surprise. But modestly priced wines—the best of them, anyway—are endlessly surprising. Why is this? Largely because we have no expectations from such wines. They are either wholly new to us or they offer new levels of achievement in zones previously unrecognized for anything special.

I'll give you an example. When I was in Melbourne, Australia, last fall I tasted a red wine blend from Australia's Margaret River district. Now, I've been to Margaret River and I know perfectly well that it is a place of great potential and ever-increasing achievement. Still, when I tasted the 2009 Cullen Mangan Vineyard (a blend of mostly Malbec with some Petit Verdot and Merlot) I was bowled over.

This wine was not merely a surprise, it was a revelation. It is an extraordinary red wine by anybody's measure, anywhere. The price? $42 in Australia. I grant you that 42 bucks is not cheap. But by today's high-priced wine standards, $42 is far from outrageous, especially for a wine of soaring quality.

You should know, however, that the wines I'm buying today are much less expensive than that. For example, I recently picked up a case of 2008 Domaine Bruno Dufeu Bourgueil Cuvée Grand Mont, a stunning Loire Valley Cabernet Franc crafted from 50-year-old vines. Cost? $15 a bottle—and that was before the case discount. This wine offered an element of surprise that wines 10 times the cost do not provide.

Two weeks ago I purchased two cases of a Spanish cava that astonishes everyone to whom I serve it. Torre Oria Brut is 100 percent Macabeo, a white grape variety I'd never previously experienced as a sparkling wine until I came across this bottling last year (it was one of my Wines of the Year in 2010). It gratifies everyone—even Champagne fans—with its depth of flavor and lemon-tinged richness. Cost? $8.50 a bottle. The surprise is, as the credit card advertisement puts it, priceless.

Obviously, a low price alone isn't enough. The real surprise lies in finding remarkable quality—and then looking at the low price. Of course neither of these surprises happens with expensive wines, where too often the only surprise is, "Is that all there is?" This is not the surprise you're seeking.

Today's wine world is radically different from the one I entered 35 years ago, when I began writing about wine. Few surprises were then available, as most wines of quality came from long-established and highly regarded districts.

Today it's the reverse. The majority of the world's most interesting wines now come from "unknown," or at least unheralded, locales. Collectively, their numbers far outstrip the relatively small pool of famous zones commanding high prices. To call this a revolution understates it considerably.

My goal now is to have a cellar filled with surprises. Ironically, that means selling my expensive wines so that I can "afford" today's really great cheap wines. Now that's a surprise, wouldn't you say?