Photos are necessary, dont jack up any prices as someone else
suggested, be far and get bids, 3 is best.
Recording conversations will not get you in trouble as most states
require One party be agreeing to the recording and that is you. If
questioned as to why you recorded him, your answer to that is it is for
contract verification, changes , and protecton.
Keep your insrance co out of it . Any claim can raise your rates.
You may have more than 400 damage but wont know till you get bids,
stop pay on the original 800 now if you can till you know your costs to
make everything fair and right, not at inflated prices or costs, of
course. I have done this many times with success with hacks.
Photo everything of importance.