Sure it is. If it wasnt it would violate the first law of thermodynamics (and every powerplant in the world would have infinite streams of serial turbines running off of exhaust stacks creating power without cost).
The work done by the turbo requires energy (taken from the exhaust stream) and ultimately from the engine itself via increased backpressure.
The sc vs turbo is an efficiency debate (as you alluded to).
To the OP - there are a million articles available about forced induction choices. There are sc guys and there are turbo guys - but the both do fundamentally the same thing: they use engine power (directly or indirectly) to compress incoming air so that more fuel can be shoved into the intake and burned (creating more power).