I would get another electrician out and have them price replacing the box vs the rest separately. 

You have no Capex budget at all, but the truth is: roofs, kitchens, HVAC all need replaced eventually even if they are new now.  

Until the zoning codes are relaxed in Memphis to allow more duplexes or small homes clustered on lots with with common areas, it will be too expensive to build replacement housing and rent them for under $750.

We own a house rented to college students and need to replace the living room furniture.  

We will replace the roof and paint the siding.

We replaced roof, some new windows, new A/C, flooring, quartz countertops, new appliances, basic bathroom remodel and gave the exterior a facelift.

Lets further supposed that the replacement cost is $1,000 with like and kind. 

@ Neil Garceau,What i will suggest is for you to look for an Asset Based Hard Money Lender that does not consider income or Credit, underwriting is based purely on the asset and its cash flow. 

Finishing property, fixing and painting holes in walls, redoing all carpet and flooring, replacing counters with granite and adding an island.

Use actual dollar for long term replacements.