According to the MLS 19023 home prices were up 27.4% in August of 2021 compared to last year, selling for a median price of $131K.

2-4 unit properties are convoluted with more than one valuation method being both the income and comparable sales approach.

Definitely not the case when being compared to the better investment opportunities.The OPs ADU will be initially cash negative.

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

Just your income from the property compared to PITI. 

You're comparing apples to oranges.

I think the decision depends on the revenue  and appreciation potential of the property vs. a comparable property local to you.

To a person they were all relieved...because of another STR on the block having been kept immaculate and they were already seeing how nice I was making it compared to how it had been for years.

And once you do buy, go back and compare to your estimates to actuals and adjust as needed.

My first filter would be comparing the cap rate of the property [this is basically the operating margin of the asset] with your weighted average interest rate [ for example if you borrow $80k @ 3% and $20k @ 9% your effective interest rate is 5%] If your effective interest rate is higher than your Cap Rate, the investment doesn't make sense, at least in the short term.