@Wes Blackwell Thank you for taking the time to comment and add some possible scenarios that provide a fuller picture to cattle ranches, pig farms, and closed mobile home parks. 

Seminars, youtube videos, and reading forums helps but rarely gives you the full picture all at once.

So I visited https://villagefarmaustin.com/ today.I've posted some pictures that I took while there.

I have travelled to the property to take some pictures of the outside.

The condensate drain and trap need to be cleaned, and the water replaced in the trap.The blower wheel needs to be checked for debris and cleaned if necessary (this requires complete removal of the blower wheel).An amp-draw test should be conducted on the blower motor and compared with what is listed.The wiring needs to be checked for corrosion and damage.The filters need to be checked  I'm making the boys send me a picture of the filter when they replace it because I can do that with the college kids!

I would have added more pictures but I think the limit is 6.

I have a portico with a leaky (flat) roof and peeling paint and a makeshift drainage/spout (someone put together some pvc pipes and drilled a hole into the balcony/porch/portico.Now, I'd like to fix the roof and slightly renovate the portico for a more durable and modernish look (similar to the one in the picture). 

From the pictures you would think maybe 2000.

I'm attaching a picture of the electrical wires I have available: 2 wires for condenser units and 1 wire for HVAC.

Like @Curt Davis says, the more information you can provide to your buyers, the easier it is for them to make a decision, so take lots of pictures and try to get as much information from the seller as possible.