I'm quiet on here, mostly a lurker but I live nearby in Medford right off Salem St. close to Medford Sq.

Because I find a good deal (or what seems to be one), and then there’s no nearby comps and get uneased and confused.

You can also look @ ads for nearby properties to give you a better idea of the market average. 

. - I’ve lived in Killeen and other nearby cities three different times for over 15 years since 1997 (thanks to the Army).

Check out the nearby members and network https://www.biggerpockets.com/meet , it will help you a lot to find partners that can help you out in investing.

This is really unique situation, the residential properties near by has different use, therefore not good for comparables. or do I let them do their market research any way?

No one can predict the future, but if you'd like I can send you a market update of how Neptune real estate is performing YTD compared to other nearby towns.If you do decide to pursue Neptune, my office just listed 3 properties there (one single family, 2 multi family) all at 60-65% of assessed value and for $175,000 and less. 

Fairview was nearby when we lived in North Dallas.

Lots of parents / family visiting that area need short term housing and there's not a lot hotels near by.

First it seems you are paying  as much as $10K more than nearby properties.