It costs more than regular gas to run, but less than half as much as race gas. So, if you do a little math; 3.5/gal x 1.30 = 4.55/gal (that's the extra 30%) for fuel that is roughly equivalent to c16 in a turbo car. That is the draw. 100oct gas is 7.20/gal and C16 is 18.00/gal. There's some math right there.
Now here is the kicker: It is only worth it if you have the capacity in your fuel system and can turn up the boost a significant amount to get the power.
2015 F150 4x4 3.5 Ecoboost
2002 Camaro SS, new turbo install in progress...
2005 Neon SRT-4, Big wheel stage 3, E85