CHICAGO HEIGHTS, Ill. – The crowd of vultures pressed in as the seal was broken, inching closer, their good-natured wisecracks momentarily silenced in anticipation as – rat-a-tat-tat, whump – the shutter noisily rolled up.

Some on tiptoes, others crouched down to sneak a view through a taller rival’s legs, all 18 almost immediately let out a quiet groan of disappointment as their eyes adjusted to the dark cave, revealing neither a pirate’s chest of treasure nor an immaculate 1957 Chevrolet, but instead a tired, cheap, wardrobe, a beige computer of indeterminate vintage, a ketchup-smeared microwave, a bloodstained mattress, a dog-eared Danielle Steele paperback and a pile of musty clothes.

It was the usual crap: the detritus, perhaps, of a messy divorce, or an unexpected death, or a hasty move out of town, or a job lost, or a foreclosure or some other combination of small, personal tragedies – something that would lead a person to hire out a 10-foot-square storage space, then default on the $100-a-month rent, forcing the sale of their accumulated junk at auction to pay off the debt.

“Twenty dollars,” a bidder ventured eventually, as the big-shot vultures squeezed out from their spots at the front of the crowd and hurried to the next unpaid unit hoping for something better, that piece of buried gold that would make them rich.

“Twenty-five,” somebody else countered, a little too quickly.

“There’s gold in that thar microwave,” a third bidder quipped. “Them socks is lucky!”

Everyone laughed at the old gags, as the manager took the winning bidder’s details, then jumped into her golf cart and sped across the lot to the next locker, one of 10 up for auction that day.

As foreclosures soar, housing prices tank and the wider economy follows, the self-storage business is one of the few parts of the property market experiencing boom times.

Following a 25 percent loss last year, stocks in self-storage already have risen 31 percent this year, with investors betting the “recession-proof” business of renting storage space will benefit from the struggling economy, as former homeowners become renters in desperate need of extra space.

Revenues at Public Storage, the nation’s largest chain with 126 million square feet of storage space more than doubled to $1.8 billion between 2003 and 2007, with its stock price massively outperforming the wider property market.

The sector has grown exponentially since the mid-1980s, with more than 4,000 new facilities opening in 2005, according to the Self Storage Association.

Association spokesman Tim Dietz said while up to half of the people using storage are moving, the business is – at least – “recession resistant.”

Auctions are a last resort for dealing with deadbeat customers, he said, adding that unpaid rent rarely is covered by the cash raised at auction.

“We don’t make any money on the auctions,” he said. “Mainly it’s just a way of clearing out space.

“But it’s fair to say that whenever the economy takes a downturn, there will be an increase in auctions.”

Even so, for every hard-on-their-luck storage space renter whose stuff is put up for auction, investors are continuing to bet there will be another two ready to move in.

Enticed by offers such as Public Storage’s first month for $1 and it’s reassuring tag-line, “Your stuff will be happy here,” many renters will end up paying far more than their stored property is worth – if the feeble prices most lots fetch at auction (usually $100 or less) are anything to go by.