(MONEY Magazine) – Among the saddest of moments when selling a house is watching the real estate broker strut off with his commission of 4.5% to 7%. But now you can turn $ instead to a growing network of brokers around the country who charge flat fees for their services. Mike and Roxanne Argenbright, a machine-design consultant and a homemaker, figure they recently saved roughly $3,500 in commissions by selling their three-bedroom, $77,500 Cincinnati home through such an agency -- Homeowners Concept -- before moving to Potsdam, N.Y. Flat-fee firms such as WHY USA in Phoenix, Help-U-Sell in Salt Lake City and Sell Your Own Home in Kansas City charge $990 to $3,500 to help you set a selling price, develop a marketing plan and handle your closing. The agencies also place houses either in exclusive weekly listings available to prospects seeking their services or with local multiple-listing services -- real estate networks used by full-service brokers. If the network produces the sale, the commission broker typically collects 3%. What a flat-fee broker generally won't do is show your home, which is a serious drawback if you have neither the time nor the patience to provide prospective buyers enticing house tours. You may also be a bit too emotionally involved to close the sale. ''Homeowners are prejudiced by their own taste,'' says Rob Toohey, a traditional real estate broker in Newtown, Conn. Flat-fee brokers make the most sense for sellers in healthy real estate markets, where houses usually sell themselves within two to three months of listing. That's because you typically must pay an up-front, nonrefundable fee of $200 to $495 (the rest of the charge is due upon sale). If you become frustrated and stop listing your home in a soft market, you will have paid this hefty fee for nothing. Or if your house sells only after your flat-fee broker links up with a commission-charging multiple-listing colleague, you may not save much money. Your total brokerage charges could equal 5.5% of your sale price: 3% to the full-service broker and the balance of your flat fee -- probably equivalent to about a 2.5% commission -- to your original broker. -- B.H.