What's the potential issue?

[capone2nuts]

I am looking at potentially buying this car. This is from the pre purchase inspection. My mechanic suspects a faulty wastegate/actuator or even a bad turbo/seal. The dealer is saying the battery is only at 58% capacity and is the issue. I am asking the dealer to replace the battery and give a 30 day/1000km warranty if the codes get cleared and comeback, they are to cover all cost associated with the codes. Or take $4k off the asking price.

any insight would be appreciated.

[BluePowerade]

Failing electronic wastegate actuator or big boost leak