Maybe it's the market, maybe you're in it too deep or maybe there's something major like code issues you missed.

I would like to narrow down a few zip codes but need a little advice regarding which areas are best. 

The property details are:- Duplex in 95677 Zip Code- 3bed/2bath each side- Not a fixer upper, but not a gem eitherI am looking for advice and guidance on: how to analyze & figure out what my max price will be, negotiation tactics for off market deals, ANY and ALL other advice for off market deals or house hacking!!

I"m seeking to rezone the lots as they are pre-existing, prior to the first zoning codes, which later came in and only granted duplex zoning, so these are legal, non-conforming but can't be converted to separate up/down "condo" sales as lenders won't loan if a structure can't be rebuilt after a catastrophic loss unless its zoned correctly as their collateral is compromised and that is the case in the county where these are located. 

It seems like it might be best to find that middle 'sweet spot' and go with the median level of finish then in your case (sounds like not wanting to invest a lot to update, and want to keep cash flow at max.)If I were to run comps and see on the high end of area rentals it meant all new countertops, appliances (high end), hard wood/laminate, kitchen cabinets etc and on the low end it meant more of an 'apartment level' finish - I personally would go for the middle road to this and maybe choose to refinish countertops, refinish kitchen cabinets and go strictly mid-range on appliances (I would pick up the extend warranties personally).In hitting the kitchen and baths, getting some fresh paint up and addressing flooring- I would know the heavy 'where the eyes are drawn to' items were checked off my list, take it all for expenses come tax time and be pretty happy to know I was right in the middle zone for the area- I wouldn't have the lowest quality of renter pool in the area, or be worried about overpricing myself out of the competition on the high end in my mind. 

Building Codes are not equal across the country and some of the newer rules are quite over the top......so he may be charging you for extra work as well.?

the bed bug ordinance went into effect January 1, 2021 - see link below.https://codelibrary.amlegal.com/codes/philadelphia/latest/philadelphia_pa/0-0-0-198057 

However, I would like to rent this out to traveling professionals aka traveling nurses, (usually 13 week contracts so semi short-term), or airBNBs (>30days the area I am located has pretty strict airBNB rules so > 30 days allow me to circumvent that). 

Do be careful though and check with your city's zoning and development codes.

You may have old sewer lines, old wiring, asbestos, lead paint, rubble foundations and various things that fall short of modern code.