Hello all, im in the process of purchasing a home..had the home inspection and found abestos insulation on heating vents and I've agreed too a $500 cap on repairs.

Im pissed because I'm sure the seller was aware of the asbestos however, did not disclose that information which is a crime itself...

I'm wondering how pricey it is to have this type of abestos removed and whats the rate for an air test? Since there is a $500 cap, i'm considering asking the seller for the air test to have piece of mind until I make the necessary repairs. Should I negotiate price? Should I demand they do the abatment or walk...Any thoughts?
For clarity..the abestos appears to wrapped around all the metal duct work inside the walls. The ductwork in plain view does not have abestos on it.