RCA Full-Duplex Conference Phone for $47.99. Choose in-store pickup to save on shipping if you have a Fry’s near you. Otherwise, shipping is between $6 to $8 depending on the location. This business-class full-duplex conference phone features 3 microphones, 100 name-and-number directory, LCD Display with adjustable contrast, 7-level speaker volume control and 3-Level ringer volume control, and a data port for parallel operation of a phone, fax or modem. Others usually sell it for well over $150.