This is more of a exercise at this point. but i am still going through the motions. originally site unseen i had a 45000 rehab based on pictures, i had a contractor friend of mine  look at the place and a rotten sub floor on the upstairs unit from a leaking roof brought rehab up to 80,000.

"Smoke detectors and handrails" is what my original realtor said to me when we bought our house. 

Motion detectors? 

The old business that was in there before has CO/fire detector.

Here we are required to use the 10-year sealed detectors.

That's why we put in smart smoke/CO detectors, water leak sensors, smart thermostats and video doorbells in our units (connected by a hub).

High power motion detector lights in the back yard. 

Bright LED motion sensing lights. 

For electric cost,  look to add a motion sensor that turns off the light when not in use. 

Could be as small as a dead battery in a smoke detector in the middle of the night (no guest wants to hear beeping while they are trying to sleep), guests can get rowdy and disturb neighbors, I have even had guests that insisted upon having someone meet them face to face when they arrive.