After years of trepidation, homebuyers are finally hitting the housing market. But, as they do, many are making the surprising choice to hunt alone, rejecting the assistance of what's known in real estate as a buyer's agent.

Many experts say this is a bad move — worse, for example, than trying to sell a house without an agent. For one thing, in most cases, a buyer doesn't pay an agent; the buyer's agent splits the commission with the seller's agent, so the services are essentially free to t...