we wont have the money to do so.
lets be a bit realistic.
Let us say that China sells each J-31 to Pakistan for 75 million dollars.Chinese will allow favourable terms and will be more than happy to spread the cost in equal installments over the say 2020-2030 period of induction.
150 aircraft will cost around 10 billion dollars and spread over ten years it comes to 1 billion dollar a year.
Pakistan defence budget is capable of this purchase if it is made a PRIORITY.