VINELAND, N.J., Sept. 17, 2010 -- So you're looking for a place to stash your cash, but a Picasso is out of the question? One of the brightest minds in American retailing, the late Donald L. Kaufman, knew a thing or two about making money, and his favorite investment was metals -- tin, pressed steel and cast iron -- in the form of antique toys.

The co-founder of K-B Toys, Kaufman, who sold his interest in the company in 1981, began collecting early toy vehicles after World War II, with the purchase of a truck spotted in his ailing friend's bedroom window. The $4 purchase spurred a lifetime of collecting that, 60 years later, has culminated in a series of high-profile semiannual auctions. The fourth sale of the series will take place Sept. 24-25 and features the last of Kaufman's prized European toy autos.

So far, the Kaufman toys have raked in $9.3 million -- the highest amount ever achieved at auction by a single-owner antique toy collection. Jeanne Bertoia, owner of Bertoia Auctions, the New Jersey firm commissioned to sell the collection, predicts the upcoming sale will push the total over the $10 million mark.

How high can the price go for a century-old rarity from the Kaufman assemblage? The top piece in one of the previous sessions, a circa-1912 live-steam fire pumper made by the premier German toymaker Marklin, had no trouble achieving $149,500.00.

"I'm sure there are many on Wall Street who'd love to have Donald Kaufman's investment brain," Bertoia said. "He had the foresight to buy only the rarest examples in the best possible condition -- which is exactly what brings the big money in today's marketplace -- and he was doing this long before anyone else saw monetary potential in antique toys."

Kaufman lived to see the first two sales of the auction series; he died on Oct. 12, 2009. The third session, held in April, drew a sizable contingent of European bidders, some of whom had to find creative ways to arrive at the auction after Iceland's volcanic eruption grounded most U.S.-bound flights.

"No one wanted to miss the event," Bertoia said. "The Kaufman collection is viewed as being at a level of its own -- like a museum-quality collection of fine art. There is no other like it."