Online auctions can be the answer. According to the Huffington Post, In 2008 alone, $15.5 billion in commercial real estate was sold via auction, and that number is likely to increase once the 2009 figures are released.
A responsible agent, doing the best for their client should not overlook the online auction process. While you may not get the full listing price, the speed of the transaction from original listing to final sale will save your client money.