Avoid the 1litre Mk2, the engine doesn't have enough power to shift the mk2 and without power steering a learner will find it very heavy.
I went for the 1 litre Mk2 Polo option for teaching my girlfriend, better power to weight ratio and easier to manouvre. Still costs too much, but that's cos of the area.
My trick is to have yourself as main driver, her as named driver (learner), then add your parents (or anybody over 50) as named drivers too. The more experienced the other named drivers are, the better, even if they are never likely to want to drive the car.