For the journey between Ely and Cambridge, Greater Anglia introduced cheaper fares last month, charging £4.90 for a peak day return for just Greater Anglia trains (instead of £7.10 for the Anytime day return), with trains at 7.30, 7.33 and 8.00. From 9.38 onwards, there is an off peak day return which is £2.30, although the service is then only hourly. The reliability has been pretty good too.
They also sell these tickets via their app, which you can get as a mobile ticket to avoid having to queue at a ticket machine.
They also sell these tickets via their app, which you can get as a mobile ticket to avoid having to queue at a ticket machine.