first take a look at car ownership rates.....I'm betting 0.1% of car owners at most do engine modifications to their cars, and perhaps only 10% of that actually have the demand for a dyno (most are just bolt-on swaps, no tuning needed)....
so if you have a million cars in karachi, there's ~100 cars that need these services.....that's app. rs.1 million and they don't all need tuning services every month or even every two months.....it's mostly a one/two/three time thing at most....