Have had my multijet punto for 5 years now.
Currently getting 64mpg its heavier than a panda has slightly more space, and can be picked up for £1000-£1500, no dual mass fly wheels or dpfs to worry about
£30 a year to tax.
Servicing costs are cheap I do my own for under £100 a year.
Brakes under £60 for discs and pads.
All suspension components are cheap.
The multijet engine is pretty bomb proof with no cam belt to worry about or pay for.
If you budget £2000 for buying servicing and repairing it over a 3 year period (which is feasible) it will stand you at £55 a month in total costs
Over 75k miles would probably work out to no more than 13p a mile
When I used to be able to claim 40p a mile I used to make quite a profit, over £350 for a months traveling.... Not bad really.
The only reason I have for suggesting the punto is they seem to be a bit cheaper than the panda for the same year, mileage and spec.
Look for dynamic models as they have the all essential aircon