If you’re in the Fulham area and fancy a good breakfast, you could do a lot worse than the Fulham Cafe on Fulham Road. Full English Breakfast including coffee for about 5 pounds. Can’t say fairer than that in London.
(head out of Fulham Broadway station, turn right onto Fulham Road, and it’s on the left-hand-side of the road after two corners and about 300m).
Disclaimer: I have no connection with this cafe apart from being a client.