Foundation issues. Need advice.

[Mark Derecho]

Found a nice house with foundations issues.  Per engineer estimate, the foundation needed to be lifted 2.5 inches.  Below is the work to be done.  The cost was quoted at $6k.  The house has tile flooring.  I'm assuming this will be damaged during the foundation lift?  What else can I expect?  How much buffer do I need to negotiate in price?  Looking for advice from those who have done this before.  Thanks BP!

(23) piers will be driven to reinforce exterior beam of house for additional strength

(07) piers will be installed or adjusted in the interior of house to help with the leveling

(07) concrete break outs to access under foundation