How much is a zone one return on oyster pre pay for underground?

Question

How much is a zone one return on oyster pre pay for underground?

Answer 1

£3 - but if you use your card for more than that, it will cap you for the lowest fair - so say you may 3 return journeys, which would be £9, it will only charge you £6 because the cheapest option would be a one-day travel card.

Answer 2

Are you returning from within zone one, or are you travelling from an outer zone.  Oyster cards are the cheapest method of travel especially after the latest fare increases.  So if you're going to travel, the best and cheapest way is to use oyster.