May be the food / lunch / dinner could be the only reason.
But look at this anomaly :-
Surat – Bandra shatabdi spl 252 kms 6.00 d 9.40 a 3.40 hrs journey @ 71 kmph Fare Rs. 465/- (timing wise no lunch / dinner )
Bandra...
more... – Surat shatabdi spl 252 kms 10.30 d 14.05 a 3.35 hrs journey @ 71 kmph Fare 465/- (assuming with Snacks & dinner)
Surat – Vasai Rd 215 kms shatabdi spl 15.00 d 18.00 a 3 hrs @ 73 kmph Fare 370/- (timing wise no lunch / dinner)
Vasai Rd – Surat 215 kms shatabdi spl 18.35 d 21.15 a 2.40 hrs @ 82 kmph Fare 370/- (assuming with snacks & dinner)
Borivali – Surat in Ahd shatabdi 6.59 d 9.40 a 2.41 min @ 87 kmph Rs. 405/- (only snacks - no lunch)
Surat-Borivali in Ahd Shatabdi 18.00 d 20.52 a 2.52 min @ 82/- kms Rs. 435/- (only dinner)
To and from timings are different, however fare remains same here for these trains.
The issue is not being made out but the facts are being blogged and debated. The fare set up information ought to be made at suitable places by the WR. Else, the people just wonder.