@Rich Bultema - Just from my experience I have not had an appraiser impact the value for an older heater/air conditioner, however, a heater without A/C (as an example) has impacted an appraisal on a single family home.

If I am reading your numbers correctly you are saying that you are cash flowing $876 annually for a $53,000 investment plus your time, risks and unknown expenses e.g. loss due to vacancy, cleaning after a tenant destroys the property, painting, carpets, utilities when it is vacant, new water heater, furnace, air conditioner, leak in the roof, broken or leaking drain pipe, sewer, water pipe, gas leak, or replace or repair leaking faucets, broken screens, repairing locks, trash removal, city sewer use fees and a lot more. 

CAPEX is for major items: roofs, furnaces, air conditioners, plumbing piping replacement, etc.  

Your competitors will have 35-45-55-or more.At the end of your current list, I found THIS:"Not includedUnavailable: Exterior security cameras on propertyUnavailable: WasherUnavailable: DryerUnavailable: EssentialsUnavailable: HeatingUnavailable: Hot water"Essentials are: sheets, linens, pillow cases, bath towels, hand towels, wash clothes, soap, shampoo, conditioner, dish soap, paper towels, Kleenex, etc..Picture count: 8 (OUCH!). 

I purchased a new furnace and Air conditioner for my only rental property in July 2018 at a cost of 6875. 

Windows are rarely opened due to the climate, and we have almost no flying insects in the desert.All monitoring-type devices, including Ring doorbells, alarms, cameras, etc.All trip hazards: larger loose rocks or bricks.Water conditioners and RO systems.Basically, if any item does not increase the rent or decrease the time to rent, we remove it.

When we first get down there it takes about a day for the air conditioner to cool the inside down. 

Because they would like to buy the house and they would like to have a brand new air conditioner, they would like to have the owner spend $8000 to put in a brand new air conditioner before they exercise the option. so they do a little sabotage secretly to make it so the air conditioner stops working in order for the owner to replace the air conditioner before they exercise the option.How do you think this situation should be handled?

Use national averages as your guide when making estimates.In our market, the two most significant costs are air conditioner compressors and water heaters.

I am looking into alternatives for AC/Heat and am thinking about the LG 23,000 BTU 230/208V Window Air Conditioner Cools 1,400 Sq.