I'm only talking about 1p a Litre BUT

... I wasted 25p buying petrol this morning instead waiting till now. BOooooo!

This is the scene of one of my favourite old photos. Converting today's price to per Gallon it would be about £5.35

That was today and this was in February 1979
https://www.flickr.com/photos/vitalsparks/6968102893/. Guess the price before you look.