RailFans never grow old

I recently travelled from CBE to MAS and back. The booking was done before the increase of the ticket price on 21 Jan 13. While I travelled from CBE to MAS by 2nd AC, I was charged Rs 35 on my ticket. However, on the return, I was charged Rs 54 for a 3rd AC ticket. Can somebody clarify why the 3rd AC increase is Rs 19 more than the 2nd AC for the same distance? One assumed that with increase of the Class, the excess charge will also increase!

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