In this case, he's cutting out paying the buyer's agent commission and the pay off for his solar.

Just curious, have you seen any investment property that have solar panels?

I had a tenant ask me to put solar panels on the house because they were going "green." 

Purchase price: $125,000 Cash invested: $85,000 Started off as a run down outdated 1 bedroom 1 bath home in Sanger - was purchased from a wholesaler for $125k - Added 1 full bedroom to the house, replaced wall heaters and window AC with HVAC ands ducting throughout - replaced old circuit breaker panel with new updated one and rewired interior electrical, replaced all windows with dual pane windows, replaced most of the doors, laid new carpeting in the bedrooms and wood plank flooring in the living room, tile in kitchen and bath, added new baseboards and painted interior, replaced all doors in the house, granite countertops, new lower cabinets, all new appliances, added rails to the front porch, converted an older closet into a laundry room / new closet, completely remodeled bathroom to make way for a new door to the new bedroom ( not shown in pics), new wall tile in tub/shower, redid some roofing, and painted the entire exterior.

I would build on your specific skill-set before I ran out and started slanging solar and security systems.  

Interior trimMEP SystemsPlumbing hot water heater/supply piping/waste pipingElectrical (panel, wiring, lighting)

I already have a 240vac panel out front behind a bush that I can add a breaker and run a line out to the parking area and install an outdoor rated level 2 charger.I beleive there is already a filter for looking for EV friendly house on Vrbo, Airbnb or both.

With propane prices being so high, i'm trying to convert to as much electrical as I can, with potential future hopes to get some solar panels as well. 

This is without factoring in the cost of hiring a property manager (I do include mello-roos, solar costs, and ~10% vacancy rate - jeez these are expensive). 

An efficiency kitchen isn't very expensive, but the the stove and refrigerator put extra demands on the electrical panel.