I’m brand new here, got the recommendation to join this site through a book I listened to on the way to work today.

I always research companies first before doing business, but that comes from my training and working on security issues, especially after having my sites hacked. 

The occupants agreed but unfortunately on the date the transaction was supposed to happen, the occupants went ghost on me.

Scour every home site available and even sites that are not know for home sales, but sales in general - you may be surprised.

Otherwise, you could also provide prevention recommendations somewhere on the lease that includes what you've mentioned above.Assuming you don't have a lawyer to help with your rental agreement you can find some sample clauses on a site such as Law Insider.

Great to have you on the site. 

I'm curious if this discrepancy is typical of other regions as well.How accurate is the data on this site?

The website 51west.properties also scores low on scam advisor ("owner is using a service to hide their identity, high number of suspicious websites on the server, registrar has a high % of spammers and fraud sites, website is (very) young, website appears to be hosted by a company with a bad reputation", all according to https://www.scamadviser.com/check-website/51west.properties...)Trust your instincts. 

In order to qualify for the Section 121 exclusion, you must have used your home as your main home for a period of at least two years out of the last five years prior to its date of sale.  

Don ,  you speak from experience and most folks on this site have ZERO experience with litigation.