I'm a fairly new investor and was looking for some advice on what my next move should be if I want to build up a portfolio of STR's.

You can find comparable sales in 2017 and use that dollar/acre figure to arrive at the fair market value then. 

To be fair I'm not super up to date on the "uber of offices" concept that you are hinting at, except inasmuch as to say "um, didn't that idea kind of die off with COVID?"

If you gift a house, the fair market value (FMV) at the time of the gift applies to the lifetime gift limit—not the amount you purchased it for.

However, I’m not sure how to accurately determine its value, given the configuration and the fact that it’s not fully rented.My Concerns:Determining Value: How should I calculate the fair market value for this type of property?

Seems like a pretty fair recommendation to me.

  :)   There's so many Gurus pitching this and that without mentioning the risks to them and to the buyers.So glad to hear re your business model being fair to the buyer.   

I'm fairly new to property management, with 1 duplex, which I have been managing for a few years now.

I'm also considering finding a seller that would pay more than me to help my father-in-law out and perhaps get a wholesale commission that I could use on my next (ok, first) brrrr, but I'm not sure the best way to validate a fair price or know what a fair wholesale commission would be.

Quote from @Aaron Wolman: Yes, these charges are fair.