This is Local London said: "While Mayor of London Ken Livingstone has frozen most prices for those using Oyster cards from next year, passengers paying cash for tickets will see the cost of trips within a single zone rocket from £1.30 to £3.
And because Oyster readers have not been installed along the North London Line, passengers cannot use their pre-pay Oyster cards and will be forced to buy the more expensive cash ticket." - or use the travelcard route as mentioned above.
So yet another reason why Ken ought to try harder to force National Rail to get fooking Oystercard prepay installed on stations that run through London Transport zones. "Mr Livingstone is discussing with the Department for Transport whether he can control National Rail services within London, and the spokesman said that if this gets the green light, then the equipment will be put in place."
"Darren Johnson, Green Party London Assembly member, has branded the price hikes 'unfair', and believes that Mr Livingstone should suspend the inflation-busting rises until the Oyster sensors are installed."