It could take around 8-10 years to produce 110 Mirage-2000s after the deal is signed. IAF might not have to pay the whole $5 billion amount time of signing the deal. The amount might be paid over a span of many years. I don't think IAF should have budget problems with it's budget increasing every year.
So M2K-5 at 40 million seems plausible.
For 110 M2K-5 it will cost india $4.4 billion.
Also, maybe IAF could go for the cheaper Mirage-2000E version (currently been used by IAF) with an option of upgrading to "dash 5" later.