"Many of the new clients are coming with large spending budgets of over $1 million," says Daryn Schnipper, of Sotheby’s. "Clients naturally drop out of the market, but for every large bidder that goes away we seem to be seeing two ready to take his place."

Auction houses emphasize the increased transparency in the way presale value estimates are derived. Tools like glossy catalogs and the Internet have made critical information such as provenance and condition estimates more easily available than ever before, and this, say the auction houses, has built collector confidence in auctions as a reliable source for watch purchases. Nevertheless, some collectors maintain that purchases on this scale ought not to depend on information provided by a single source, particularly one with a financial stake in the outcome. Collector groups and communities (many of them Internet-based) and, in some cases, the watch companies themselves, provide alternate, albeit labor intensive, paths of research.

If a curious mixture of rationality and emotion raises the cost threshold for buyers, a similar psychological concoction determines which brands and models attract the greatest attention. Pieces from Geneva manufacturer Patek Philippe garner the top prices. The company’s consistently high level of quality and historic model variety is simply unmatched, earning the brand an almost obsessive degree of collector loyalty. The remaining canon of brands that attract serious investment has always lagged rather far behind, but there are important signs of activity in this group as well. "Vacheron Constantin has always had an awareness among collectors for its great history and periods of very strong design," observes Patrizzi. "Now there is much more interest in the brand, as we’ve seen in the last few auctions. Part of this may be the upcoming 250th anniversary, but I see people looking at the brand as an alternative to Patek Philippe, particularly as the prices for those watches are so high."

But not every complicated model from these brands attracts equal attention. Certain types of complications have come in and out of vogue, adding an element of fashion to the valuation equation. Since the interest in the luxury watches is partly predicated on their capacity to convey prestige, some models have attracted the most attention. "In my opinion, people’s tastes for watches at auction resemble the Chinese market in the 18th and 19th centuries," offers Schnipper. "The pieces then weren’t acquired to tell the time. Rather, they meant to overtly display mechanical sophistication and status with features like automatons." Likewise today, the stopwatch function of the chronograph and the complex, gravity-compensating mechanism of the tourbillon create an interesting appearance in a watch and are preferred over more subtle pieces, such as chiming repeaters, that have the look of an ordinary wristwatch.