A turbo setup is going to involve a lot more development and money than a supercharger which is much more of a "bolt-on". Turbos have way more HP potential than blowers and don't rob any HP to turn but it's hard getting them to provide good boost at low RPM if you want massive HP. Superchargers, however, can provide instant boost at any RPM (especially Roots/Screw-type blowers) with typically more torque available everywhere in the powerband and are more straightforward to install.
