$350 for +30 HP is a bargain! Keep in mind that if it sounds too good to be true it probably is. We were promised +49HP with the supercharger. I didn't dyno my pre-S/C'd VX, but after the installation it dyno'd 187 rear wheel HP, much to my disappointment.
Talk is cheap. Show me the dyno results, and I'll show you the $350.
Rick