I might kill the party here, but ToursForSingles.com was created in November 2015 and now parked at SEDO, where you can buy it for under $600.
It means that someone who paid you $1000 for it in 2014 dropped this domain at the end of the year. It's possible, but highly unlikely.
Selling domains is not as easy as described. For every one you sell, there's 100s that you fail to sell.
The other misconception in your story is "As soon as I had the domain in my account I began looking for qualified buyers. ".
Usually you do this before you backorder domain, not after.
They dropped the domain, someone else picked it up, it happens every day.
Why would I spend time looking for qualified buyers before I had the domain in my account? If I lost the auction or missed the drop then that would be time wasted.
I bought a domain for $20 and sold it for $1000, whatever else you are saying is nonsense.