Just calculate the average price/sqft and use this, but this isn't good because some out of date also get sold, and the likesFinally, how closely do investors follow the 70% rule?

In your case and my case in the example sited the insurance rose higher than could reasonably be forecast.  

We are renting them on Airbnb and on our site as wedding but yes Airbnb does not have that option yet.

I just found this site on Google search while trying to get more information about Mr.

We always leave those extensions and dates up to a client's CPA.

I don't really come on this site much anymore.

Its generally retail medical operators, so we include things like the market dynamics for our use and why statistically the market and location of the site will be viable form a business case standpoint, and speak to how the startup has enlisted the help of an EMR or other such consultant to help in their general rampup and ability to bill/get insurance contracts.  

@Jeremy C.I looked at their (JLL's) website and see that they have a history dating back to 1783 in London England and have offices in DE, MS, DC, & VA.

Yes many places taken but not all land is developed , still many plots left passed Rosa nearing the lagoon and on the street on opposite site of beach. 

You can also sell them on sites like paperstac, debexpert or others as well as brokers like Mission Capital, Rams or Phoenix.Depending on quality of paper and interest rate will determine sales price - also I would say self servicing can have a negative impact on the sales price as the major players in the space are not fond of self servicing.