i'd say ride your car out till you know its gonna die soon, i'v been doing that with my stratus for about 4 years now and its got 320 000km's on it, youd be suprised how long you can push some cars if you get lucky
i also am paying for school at the moment and need to buy a car, i'v been told by a couple mechanics to look at 2000+ grand am's and oldsmobile aleros, their cheap, cheap to fix, reliable and last a long time
on the autotrader i can find 2000 alero's with 100 000km's for 4700$ 3.4L V6 engines... (i'v heard bad things about the smaller engines breaking down)