I have it for some years now and believe me it is best considering economy. You restore it with good quality parts you will never pay short visits to mechanics. It is far better than any local car in terms of maintenance.
I remember i installed new shocks some 4 yrs back and have traveled all provinces/cities every corner name it Quetta, Nagarparkar, Swat, Islamabad and it never let me down. MashAllah still runs like a charm.
Since you're in Karachi I won't suggest you as a daily runner coz the city traffic is worst now and you'll curse yourself having MT and a non-power steering machine when stuck in traffic.
I myself use it for only weekend short long trips.
1- mechanical parts are available, new are of average quality. You have to find minimal used parts from Shershah or find new from few reputable shops at Plaza.
2- Its reliable 200% as its a rear wheel so the maintenance cost is half compared to a FWD. Don't go for a rusted one, rightly said by @rare . Denters will screw you up. And it's too hard to maintain it if the center does an average work coz being a coastal city it'll get rusted easily.
3- ride comfort is outstanding. New models can't match ke70. I've driven on rough roads Nationwide hence claiming with experience.
4- Buy good quality door rubber seals so the cabin remains cool for a long run. And also complete AC accessories. Then it's good.
5- fuel is approx 10km/litre might be good beyond this on highways and if driven with soft pedal or if we'll tuned and only running only petrol.
6- price can vary depending on condition.
Being a Karachite , and a friendly suggestion with experience. It's now a 36-38 yrs old vehicle so stay away from rusted ones. Be cautious when buying.
And it's not a daily runner anymore for this city.
Buy an automatic small car for this daily purpose.
Rest it's up to you.