As the train leaves Sheffield before 9.30, half fares do not apply (although they will from Meadorwhall). The fare is £4.60 (£3.05 with a railcard).
The fare from Conisbrough is £4.30 and half fares and railcards apply.
For some people it will be better to buy a South Yorkshire Travelmaster Gold £7.50). This can be used all day on buses, trams and trains
David and Leonie.