Bear in mind a 106 has no power steering either so feels a lot heavier at parking speeds than you'd think. The sis in laws 106 1.5D is the 3dr dark blue you are on about... you don't want to know how little we paid my mate for it *YEARS* ago... put it this way it was in your budget THEN
You can get cheap Foresters, but then they'll not be any different than an Impreza to run. Our other main car is a Leon Cupra TDi, but even the "normal" tdi Leons are fairly cheap to run (cheap tax, cheap insurance, huge mpg)... only potential issue is the purchase price, but they are still fun to drive. Actually thinking about it I think one of the guys at work (who has a 90 or 110bhp one) was thinking of changing for something else.
Heard from someone who had a Panda (new style) that is seriously cheap for road tax and huge mpg as well, only issue again is going to be the purchase of something that new though.
TBH, having run three cars at the one time for our family, an "extra" car just ends up costing you more money. Bear in mind you'll suddenly have to pay out double the insurance, double the tax, MOT's, servicing, etc on two cars. Okay you end up putting less miles on the scoob but is that really worth it?