When you apply for different universities then they also charge you for aptitude tests. Plus last time an attractive organization decided to bear NTS charges themselves was NAB in summer 2012. Turn out for that test was like 12-15000 candidates all over pakistan. That is like around 10 million Pak Rupees. So I really dont think that organizations can afford that. Plus I remember that many candidates who appeared in NAB test were not even eligible for the post but still applied because test was free.

I think 800 that they charged for state bank tests was un reasonable but 500 is fine.

However I personally believe that best method for NTS will be to charge 1000 per candidate for an annual test conducted by NTS. Score of that test should be valid for one year and candidates can put it in their resume while applying at Pakistani organizations.