Estimate for Interior Full Gut Rehab and Permit Issues

[Filmon Michael]

Hi All. I have done some light to moderate rehab but not full gut job before and your help on giving me rough cost estimate would be highly appreciated. I am looking at an interior full gut rehab. It is 2000 sqft 5 bed 2 bath SFH with lots of potential in Southern Orchard. The good thing is all demo is done and framing is also completed. It has new roof and new windows, too. In addition, new rough PEX pipes, PVC pipes, electric wires, and HVAC ducts has been run. But when I checked city records, no permit was pulled for the work done so far. I think the city has flagged the house for code violation because I saw NOT SAFE sticker on the door. So, I am assuming it will need all kinds of permits. My questions are: 1) how much should I budget for such kind of rehab - all work to be done by licensed people with city permits pulled. 2) if I end up buying the house, will the city fine me for the work the previous owner did? If yes, any idea how much? 3) Is there any risk I should consider in pursuing such deals (I feel like it is a half backed potatoes). Many thanks!