Don’t forget that £10 is before taxes/fees/charges.
On a £444 LHR-JFK return with BA, the taxes/fees/charges amount to £357 so the actual fare is just over £110.
LCCs haven’t yet succeeded on the transatlantic because the margins are so slim. The bulk of the total price is accounted for by the many extras charges.
As I wrote in our Snapshot page last April, People Express the first serious LCC to fly transatlantic, charged USD149 each-way for LGW-EWR. But that was way back in 1984 when the taxes/fees/charges amounted to just a few dollars.
So on that basis, BA today is charging less than People Express was in 1984 !
Yes it is true that any LCC entering the market now will score in the summer months (when all the conventional carriers hike their prices) but what about the rest of the year ?