Well, the fare is not only for a faster journey, they have to know abt the features of Tejas.. It ain't an ordinary Chair Car. The cost of its features do matter,whether useful or not. Catering charges would also come into play.
And people cannot just say make running time 6 hours like that. Line MPS is 105-110 only. Or else SR can make time table of 6 hrs and run with a delay of an hour. :)