Alternatively, if you have a van and time, buy furniture and accessories on Craigslist, and once you have sold the house, sell the furniture again.

I would highly consider buying another property for yourself in San Diego with either a secondary unit that you can rent, or better yet, a property that can is a candidate for an accessory dwelling unit (ADU).

Actually it depends if it is inside your dwelling and not an accessory building it is considered all eligible except you will have gain from the depreciation taken. 

New paint, maybe new tile floor, matching accessories: towel bar, tp holder, toothbrush glass, flower vase or basket, and soap dish.Then bright colored rug, coordinated shower curtain, towels, soap and silk flowers.Tie the towels back with rafia twine, place a flower in twine.

I've been in the Factory built housing industry as a California general & manufactured home contractor, manufactured home dealer & developer, California real estate broker, property manager and investor for the past 50 years in one capacity.I a currently negotiating the exclusive distributorship on a line of Prefab Accessory Dwelling Units (ADU's) aka granny flats, Tiny Homes, etc.

I'm trying to confirm what we might be required to do in order to make this property suitable for a small 380 sq ft accessory dwelling unit (to act as a short term rental). 

Or cash out and pocket maybe, $80K this Spring if I got moving.The real reason I got curious about interest only is that the woman I am trying to buy from has a house that I really covet.

Construction costs are well defined and unlikely to budge, I'm a commercial contractor and the GC on these and a significant amount of materials are already acquired.I can always hold them both which I'm considering...just curious what cap rates I need to shoot for (which will affect my direction on interior finishes and parking plans) to make them the shiny new things on the block that are coveted.

@Paul the A stands for Accessory not Affordable, I guess. 

@Timmy Fritz if you are occupying a single family home with an "accessory" unit then that is 100% totally fine.