Your idea of a cheap commuter car is very different to mine. I paid £350 for mine, five years ago. Probably spent £700 on maintenance in that time, and fuel averages 15p per litre and 40mpg. I expect it to last many more years. 
True, as long as you don't want to commute, or travel for business into most of the major UK cities in the near future. For example the Birmingham congestion charge/clean air thing/not-so-stealth tax would add £1800 per year to your commuting costs.
I can't deny that there is probably(?) no cheaper way to run a car than the way you run yours, but its also true that not many people, myself included would go to the level of effort required to run a car in the way you do. Different horses for different courses
