It's value is strictly based on the comps in the area.What have other rehabbed 4plex's sold for recently?

Oakland has strict rent control laws, like San Francisco, Berkeley, and many other cities, however there is an exemption for both duplexes and triplexes when the owner lives there as their primary residence.  

We discovered that very many of those locations had really strict restrictions for STRs, such as can only rent one time per year and must be at least 30 days.

It's safer for the option fee to be strictly the cost of purchasing the option.

Should I strictly just use zillow/real estate postings, or is there a better method that you would recommend?

However, Decatur is SO freakin' expensive (but the other areas like Midtown & Beltline are crazy $$ too) that it's not going to be fantastic strictly from the investment point of view. 

It’s usually not cost effective to submeter the water and some states, like Mass, have strict regulations for charging water to tenants.  

I am strictly a buy local person.

@Michael OhmanAre those strictly fees, or are there pre-paids and escrows going into the $5K?

That's tougher (not the prepaying part) in a strictly small real estate entity.