The "ABC fee" (administrative brokerage commission), of $149 and up, is becoming increasingly common in some real estate markets. Defenders of the fees say brokerages have instituted them in order to cope with the rising cost of providing services and smaller commission splits with agents. As long as they're properly disclosed, they are both legal and ethical, they say. 

Brokerages that decide to charge the fees seem to be running the risk not only of lawsuits by consumers, but of alienating their own agents, many of whom see them as "junk fees."

In what's become standard practice at a growing number of real estate brokerages, homebuyers and sellers are being asked to pay flat fees of several hundred dollars per transaction on top of the percentage-based commissions they've traditionally been assessed.

The fees can come as an unpleasant surprise to consumers, and some have charged that they violate federal law. Many real estate agents don't like the flat fees, either-in most cases, they don't receive a cut, and some end up paying them out of their own commissions.