1) It's old and expensive to maintain.
2) Prone to sanction
3) Difficult to get parts like F-16 because not built in huge numbers like F-16s.
4) J-10 4.5 gen jet with TOT is available and no strings attached with it.
5) Can not be customize like JFT/J-10.
6) High life cycle cost due to closure of production and parts.
7) Can't face future threats posed by IAF i.e. Rafael & Super Sukhoi, means no True multi role capability required by PAF.
Again... its not a confirmed news, but suerly it has served as a tool for mominoon to unleash holy war at non-momin mirrages, otherwise the deal if and when it happens, is only going to deliver good to Pakistan.
Your listed points are just empty words, my reply for the sake of confused ones:
1) Pakistan is already maintaining around 80 of those so called expensive, if somehow PAF won this speculative lottery, most suerly older frames would be replaced with younger ones. If not than PAF will have no choice but to continue with same old !
2) If its difficult to buy parts, than its for all operators alike, but i doubt its difficult to buy parts. Without confidence PAF will not ask for it, specially when JF-17 is available. So all indicators tells your concerns are not accurate.
PAF probably will win lots of spares with the deal.
3) Integrating new platform is not cheap and neither fast. J10 has no place in PAF.
4) You have wrong imaginations in regard to the term 'life cycle cost'. However, i see capability of PAF multiplied.
5) No need to modify... they already come with all goodies and capabilites, need of which usually lead to modification.
6) War is not about dual of two wrestler and with mirrages 2000-9 we only got to improve, multifolds.
Goodbye.