Negotiating After Estimates

[Peter Rowell]

I need a little help finding out the best way to go about renegotiating the price after I have had estimates done. Some background info:

House is a 2 unit that I plan on house hacking. The original selling price we agreed on was $216,000. I asked the contractors to write up everything so I would at least have the option of bringing each piece to the table, and the total came back just around $30,000. Some of this stuff is more cosmetic while other things are a bit more functional (plumbing, chimney repair). 

My question is, what is the best way to use the estimates in renegotiating a price? Should I come to the table with everything to set a stake in the ground full well knowing they probably won't go that far? I obviously would like to get the largest credit possible, but I don't want to alienate the seller by asking for something ridiculous. 

Also, would it make more sense to ask for them to fix it versus a credit? I'm not to keen on this as I would like to select the contractors who do the work, but if it would help my negotiating power, I would be open to it. 

Any thoughts, questions or comments would be greatly appreciated. This is my first house so I am without any experience to rely on.

Pete