Just fix the roof, give it a good cleaning with appliances off of Craigslist make sure plumbing, heating and cooling works and is safe to live in (no bare wires, black mold, smoke detectors etc..) when you are ready to sell it than that's when you would want to upgrade it.Good luck Wishing you success;) 

I've been in homes that smelled pretty good on the day of move-out but two days later reeked of animals or smoke!

I encourage you to do the research yourself but from the what I remember reading, HUD says the only thing that needs to be changed is the drywall and the smoke detectors.

 (9 years total)-Even though he promised he would never smoke in the house, he confessed he would sometimes smoke in the bathroom with the fan on when it was too cold to go outside.  

I'm not saying they need to live in a million dollar mansion, but something middle class and neat     Look at how they present themselves, are they somewhat clean cut and neat or are they toothless and chain smoking cigarettes?  

The building code may also want you to use some special caulk/sealer between the door frame and the wall, before you put the trim on; this caulk swells up when hot to block smoke and gases. 

Not unless I come accross a smoking deal.

This in common with people who smoke cigarettes.

They did not install any carbon or smoke detectors. 

That is a smoking rate.