Average rent in my area for a 3/2 is $4,000 - $5,000 a month and with the attached 1/1 ADU could rent from $1,800 - $2,500 a month.

@Neal DaftaryWhat are the comps in the area?

I would recommend Logical Property Management they are a member here on BP and not only be a good PM but Drew can help you with a lot of knowledge that he has with all the years he has been doing it. 

Nobody does it in our area. 

We are also in an area with a low entry point for home buyers so someone thinking of spending $2000 or more for rent is also in the market to potentially buy a home as well which makes the "higher" end rentals a bit tougher to fill except for folks that are building their Dream home and not done yet or in OKC for the short term for a job or family situation.  

Obviously find a deal, but how should I go about doing that in a smaller area?

I can talk about the Triad area of North Carolina. 

I am interested in establishing a Short-Term Rental (STR) in Oceanside and noticed on the City website that STRs are permitted only in the Coastal area.

I am narrowing down my areas for investing. 

One common advice I have noticed is purchasing a duplex or multi family home in your area or at least 30 miles within proximity.