The Price is Right host Bob Barker, 78, underwent surgery yesterday to relieve discomfort from an enlarged prostate at The George Washington University Hospital in D.C. Barker, who is expected to make a full recovery, is said to be "resting quite comfortably." Dr. Michael Manyak, chairman of the hospital's department of urology, assured, "I expect him to be up and about very soon with a return to California in a few days."