When you write about wine, you sometimes get to taste the really expensive stuff. I’m not talking filet mignon or even white-truffle expensive. I’m talking splurging like Diddy-in-a-diamond-hoodie-on-a-yacht expensive.

When a collector shares one of these bottles with me, friends later ask, “Does it taste like [insert obscenely expensive price]?”

The honest answer: It doesn’t, at least not to the untrained palate, and probably not even to most trained palates.

The lesson here is that while the price is often reflective of a wine’s quality, it is so only up to a point. And even when a wine is of high quality — from the best grapes handled by the most talented hands — it doesn’t mean that you are going to automatically taste its full price. In fact, some of the most-prized bottles can evoke qualities — think soy sauce or pencil lead or even a barnyard in August — that are off-putting to the uninitiated.

So next time you’re thinking of ordering that $50 bottle instead of one that is $30, or when you’re embarrassed about ordering the least expensive bottle, consider these non-quality factors that play into a wine’s price:

• Scarcity: When wine is expensive — and especially as costly as the bottle described above — you’re also paying for the privilege of being one of the lucky souls who can lay their lips on it. It’s simple supply and demand.

• Marketing: Some higher-priced wines, including most top-tier Champagnes are no different than Prada loafers or Gucci handbags: They are luxury goods with expensive marketing budgets (glossy ads and beach umbrellas) that are built into the price of each bottle.

• Pricing: Some wines are priced more expensively to make people value them more. A few years ago Stanford Business School did a fascinating study in which subjects registered more pleasure in their brains when they were told a wine was more costly, even when it wasn’t. The power of pricing is powerful indeed.

Every week, Mark Oldman -- wine expert, acclaimed author and lead judge of the series The Winemakers -- shares with readers the basics of wine, while making it fun and practical. In the coming weeks, he'll tell you what to ask at a wine store, at what temperature to serve it and share his must-have wine tools.