Agreed, CBR 150 R is overpriced. However, Inazuma price is very good considering it's a new bike. I personally would avoid getting the GS500 or Bandit 400, simply for the reason that in this range you will only get trashed bikes in Pakistan. No one will sell a good bike in this range.
Secondly, GS500 or Bandit 400 will be difficult to use as a daily ride. If you are moving up from CG125, you will have to spend a lot more on monthly fuel cost if you want to use it as a daily runner.
On the other hand, a new Inazuma will do 40 km/l, which is about the same as the mileage a CG125 will do +- 5 km/l. And Inzauma will be extremely comfortable to use as a daily runner.
Check OLX, as some people are selling their Inazumas for well under 6 lacs with barely 200 kms on the dial. If you can strike a deal with one of them for about 525,000 - 550,000 Rs. I think, you would be happy and have a trouble free ride for at least 5 years if you maintain it properly.
Rest is up to you.