I think that's a bit pricey too, but then I don't live in London and you will pay more there.
It would be interesting to see what the cost would be if you made to Birmingham though.
You are in for a real eye opener on fuel costs if comparing an auto beamer and a diesel Polo, they are also very pricey to have repaired.
If you are running on a budget as you say, I would give careful thought about your next car.