Maybe it’s the fault of Antiques Roadshow, or eBay, but everybody seems to think their house is full of hidden treasures. The most common question I receive, after, "what’s the best bourbon" is, "I found this old bottle of such-and-such, how much is it worth?"
Unfortunately, the true answer to either question usually does not satisfy the person who asked it. I like to say that the best bourbon is free bourbon. My answer to the second question is equally oblique but not as witty. It contains a lot of 'maybe' and 'it depends.'
The secondary market for American whiskey and distilled spirits in general is rapidly changing. It is complicated by the fact that, in the United States, it is illegal to sell alcohol without a license, so there is no legal way for collectors to buy and sell. There are collectors, they do buy and sell, and prosecutions for such transactions are rare, but the at-least-technical illegality of it all keeps the marketplace from being more orderly and transparent than it is.
Most of the action is on eBay.
Because the market is underground and it's hard to track sales reliably, it is almost impossible to appraise a particular bottle of American whiskey. An appraiser has to know about recent sales of the same or similar objects to estimate what a future sale might bring. Without that market information you can’t make appraisals with any confidence.
You can get a very general idea about prices based on personal contact with actual collectors. The most desirable and valuable American whiskeys are pre-prohibition, prohibition-era medicinal, and post-prohibition whiskeys from distilleries that are now closed. A fourth category is limited editions from present day distilleries.
Bottles in all of these categories re-sell for between $100 and $1,000 each. Although pre-prohibition whiskey is generally the rarest and most valuable type, hundreds of dollars have been paid for bottles produced as recently as the 1970s. Whiskey made at Louisville's Stitzel-Weller Distillery, for example, is highly prized.
When you are paying hundreds of dollars for something, as opposed to thousands, you usually just trust your instincts and take your chances. It’s hard to justify much investment in authentication at those prices. In the world of Single Malt Scotch collecting, where prices are much higher, fakes have been a problem.
In American whiskey collecting there are two very active but equally idiosyncratic subsets, Jack Daniel’s collectors and Maker’s Mark collectors. Both producers encourage collecting (but not, of course, any illegal activity) by issuing many limited edition commemorative bottles.
It might be fun if American whiskey collectors could openly engage in the buying and selling that is the essence of collecting, but that seems unlikely given prevailing attitudes about alcohol.