Which Is The Cheaper Option

[Dee Sa]

my pal and I are going to the Ideal Home show today, she lives out of town so has a free bus pass but not for the underground, is it cheaper to buy a return ticket Barking/Olympia/Barking or a travel card.
Luckily my freedom pass entitles me to both.

[dzug2]

A bit late now but for future reference:

travelcard £12 zones 1-4

single cash fare £5.80

Oyster or contactless bank card: £3.90 peak £2.80 off peak single

Oyster has a £5 deposit

[dzug2]

Oh and oyster/contactless cap at £9.20 for the day