I think the £3 mark is a sticking point for most, for London £3 may be cheap, but not for the vast majority who do not live there
A few years back in Guildford I nearly died when they wanted over £3, but no doubt London prices spill over that far
But I suppose it is all relative, as a reformed smoker I was staggered to see fags are over £5 a packet, last time I looked they were 4/3d and beer was 1/3d a pint
For younger viewers that is 22.5p & 6.5p respectively