It’s all marble, the floor and walls.Now that I see yours is a rental, I’d just swap out the mirror, paint the vent, new light fixture, maybe new faucets, paint existing vanity.

And each of them follow a similar pattern.

Viking appliances adorn the gourmet kitchen which features marble surfaces, custom inset furniture grade kitchen cabinetry, pot filler, wine fridge, and built-in micro/drawer.

Professional Jenn Air appliances adorn the gourmet kitchen which features marble surfaces, custom kitchen cabinetry, pot filler, &wine fridge.

The top floor offers a master, a walk-in closet, and marble en-suite bath.

This beautiful sun-drenched bi-level unit features stunning stained hardwood floors, spacious bedrooms, a luxurious marble bathroom, updated kitchen, with granite and Samsung stainless appliances.

I have been showing new homes to clients for the past few weeks and nearly everyone has a high quality LVP in some type of wood look alike pattern.  

Look for:Close - within a half mile, ideally.Closed - actual closed sales, listing prices aren't good data points.Comparable - similar bedroom count, both with and without an ADU (b/c that's what you're trying to research).Recent - the more recent the sale, the more relevant the data point.So you look at your two lists, spot patterns, find the median, compare the two median sales prices, and boom that's a solid ballpark.If you want to look at "Do I build a studio ADU or a 1br ADU?"

Keep talking to as many people you can until you see some patterns and can make an educated decision.  

With your fact pattern (purchase one unlevered property), I would look into converting the traditional 401k to a Roth (depending on the size of the 401k and your tax situation in that year) and investing the combined Roth in the rental property.