This is bogus if buyer and seller are independent parties (if the parties are associated then I understand setting true value) as there is usually a reason for the discount purchase (risk items like unpermitted work, crazy low rents in rent controlled area, hoarder, heavy need of rehab, etc).  

A lot to unpack but my overriding 'advice' for what it is worth is to make sure you seperate the values of the park and the tri plex and analyze independantly. 

I would approach a couple of Independent Agents (represent multiple companies) that write both Personal and Business Insurance.  

Always verify and seek independent confirmation of anything you're being sold or told.

I don’t see how he could simply independently come up with such a high price without discussing it with me first. 

Renting for all my independent life now, I've noticed rentals I've found were on certain platforms being advertised, like craigslist, apartments.com, Facebook marketplace, and landlords posting to their personal social media accounts.However, I can't imagine these avenues being the only advertising methods, when you have something like vacancy to fill.

Find a commercial independent broker, they’ll get you on the right track.

I have re-sparked my desire to become financially independent through real estate.  

Works just fine for me and the solar panel can be directed independent of the camera which is nice.

Play the long game but realize that maximizing long term net worth has to stop if you want to be financially independent.3.