Drive to a petrol station and tell them you have no money and that they can walk or buy some petrol.
Nice idea.
I just told one of my mates £4 (20 mile trip) and he goes - "Four quid? It doesnt cost that much! I think two quid is fair enough mate." PFFFFFFTTTTTT!
Told him to try and get a taxi cheaper


then fair enough, but it's not worth falling out over.
(Ok saw that Ninja edit there - thought you were aiming that at me lol)