A couple of more quotes from the Yahoo article:
"The city, which has lost more than half its population in the past 30 years and struggled with rising crime, failing schools and other social problems, largely missed out on the housing boom that swept much of the country in recent years.
Prices have gained less than 2 percent per year in the five years since 2001, when the auto industry entered a renewed slump"... and :
"At least 16 Detroit houses up for sale on Sunday sold for $30,000 or less. A boarded-up bungalow on the city's west side brought $1,300. A four-bedroom house near the original Motown recording studio sold for $7,000."
There has to be opportunity here. If the auctioneer was right about the lumber in the house, one could buy the house, take it apart, and sell that lumber. I know from a friend in the design business that there has been a market for distressed lumber of a certain age, where such wood commanded premium prices. With metals prices still elevated, the wiring in these houses ought to be worth something, as well