Reading headlines about $100,000 bottle of wine selling on the block can easily make you feel as though a wine auction is a wee bit inaccessible. This happens especially when you see 10 bottles of 1945 Château Mouton Rothschild go for $343,000. Then you might be surprised to know that auctions can be a good way to find hard-to-get vintage wines at a bargain.

Why buy wine at an auction?

The main reason is that the range of fine and rare wines offered at auctions exceeds the typical stock available at retail. Moreover, auction prices generally fall below retail levels and occasionally even below wholesale. Sound intriguing?

Know what you want

Before you participate in an auction, determine your objectives. Are you filling in gaps in a pre-existing collection? Are you looking to increase your cellar inventory? Are you buying for investment's sake? If you are starting from scratch, which wine regions do you wish to concentrate on? The lack of a concrete plan may get you sidetracked.

Know what it's worth

Smart collectors carefully cross-reference retail prices, previously realized auction prices, and estimates. There are several online wine search engines that assist collectors with this task. The Wine Spectator Auction Index is a good means of analyzing current auction estimates and results. The print version records high, low, and average prices for more than 160 frequently traded labels. The online version, called the Auction Price Database, covers approximately 10,000 cellar-worthy listings.

Don't expect a bargain much below the estimates

Almost all wines offered at auction have a reserve: a sum below which the wine cannot be sold. The reserve is usually set between 80% and 100% of the low estimate, and never above it. So don't expect to snare a case that is below the low estimate. If a lot doesn't meet its reserve, it won't be sold. In auction parlance, this means it will be "passed" or "bought in."

Some bargains

Names, regions, and vintages to look for include older California cabernets, such as Robert Mondavi reserve (1969, 1971, 1978, 1991), Ridge Vineyards Monte Bello, Diamond Creek Vineyards, and Heitz Cellars. Bordeaux vintages 1996, 1999, and 2001 from the second through fifth growths can also be acquired at reasonable prices. Lesser-known Italian reds, such as Super Tuscan Castello dei Rampolla Sammarco, are also a good buy. Christie’s Sept. 13-to-27 online sale features a 24-bottle lot of the 1995 with an estimate of $800 to $1,000. Chablis, some Rhone wines, and Alsace whites are all undervalued, especially in online sales.

But remember: Buying wine at auction can become addictive.