Roland Perry wrote

This is going to sound extremely dumb, I know. But when did a simple
Z1
tube fare increase to Two Pounds? Well, that's what the machine at
Paddington charged me to go to St Pancras.

4 January 2004

£1.60 using Oyster Pre-pay, ten Z1 for £15 (tube carnet)

Not sure if a tube ticket bought with your rail ticket is cheaper

--
Mike D