He hired some additional help and said it would take him a week(I estimated 3-4) to finish. 

I'll tell you right now, I wouldn't spend any additional money on staging. 

Multiplication is better than addition.

What additional data would you gather remotely? 

PM me if you would like additional information.

In addition to a legal egress window, a bedroom must also have a closet.

You can also structure in some additional terms about who and how significant repairs are handled, but that will also tend to tip in the owner/investors favor.* When selling a property on a lease option, realtor commissions are not necessary.* Check your state laws and talk to a REI attorney and escrow/title company about facilitating the transaction and all the needed paperwork for your area.

I think you will see my profession shares some common attributes with yours.https://carlozgil.com/from-musician-to-investor/ If you are a musician or once were, reach out!

( addition tore off, or are you exaggerating the roof)  based on your project details, id guess 45k+ in rehab .... building a second story would be out of the picture for me.  

At which point I would have to come out of pocket ($18k additional for $80k total renovation) to succeed in renovating the property to its full appraisal potential.