You can have balanced in/out without having a fully balanced design and still enjoy the advantages of a balanced design. For balanced input all you need are (input) transformers; supposed advantages are rejection of noise and hence a lower noise floor. But decent transformers by Lundahl and Jensen run about $200/pr so adds about $400-500 to the end user price.
And as it is common knowledge on Head-fi , almost all the top tier headphone amps offer balanced headphone out, (that does offer advantages) but most of these amps are not truely balanced i.e. have two identical circuits ( 180 deg out of phase) for the positive and negative sides for each channel. So obviously yes, there are other ways to achieve balanced out without the extra circuitry and get similar results. (hint: by tapping t)
Edited by gurus - 6/18/12 at 6:46pm