Firstly, these hatchbacks shouldn't be evaluated on HP only, since these aren't meant for drags or anything.
Secondly, Vitz 1.0 3 cylinder is less than 70BHP, not 100+. I'm not sure whether you're talking about 2SZFE (1.3) 4 cylinder, I've owned them both in the past and there's a huge difference between these two.
Thirdly, the correct comparison would be whether you're willing to dish in that extra PKR 0.3 - 0.4 million to upgrade to Aqua, which is a bigger and better option than Vitz.