Investing in real estate in actually starting, managing, and marketing a company. 

An ADU could rent for an additional $1,200–$2,000/month, depending on the local market, potentially doubling the property's cash flow.

I live in a very expensive market (Seattle, WA) and I am looking to invest out of State.

In high barrier markets, rents have gotten stronger but not the double digit growth we had seen, which was an anomaly.  

Some renters may hesitate, but if the rental market is strong and insurance is covered in your numbers, it can still work.

It works...but any marketing works, it just depends. 

We weren't super happy with anything we were seeing on the market, so my husband and I had just started writing letters and looking off-market... until we saw this property.It'd been sitting on the market for months.

How valuable is this location in that market? 

Market forces are pushing and pulling but not a source of anything breaking.

There is no one size fits all answer for this question, market to market, and property to property are all different.