In aid to the orginal poster.
There is a Virgin trains service from Rhyl to Bangor at 7:16 in the morning. This may well have advance fair availability saving you some cash. Then if you buy a single back in the afternoon you may save a few pennies. Unfortunately the timings of the virgin services don't correspond to leaving Bangor in the evening. Nothing in between the 14:20something and the 20:20something departures.
There is a Virgin trains service from Rhyl to Bangor at 7:16 in the morning. This may well have advance fair availability saving you some cash. Then if you buy a single back in the afternoon you may save a few pennies. Unfortunately the timings of the virgin services don't correspond to leaving Bangor in the evening. Nothing in between the 14:20something and the 20:20something departures.