Than, feed all that into chat GPT too formulate into a "How To" that I will next sell to the masses. 

I live in Harlem but work downtown so if I have to go to the building it is not too bad after work.

Even if PS had 100% accuracy, it wouldn't matter.It is about whether or not these people are motivated and I promise you 99.9% of these people PS will feed you are NOT motivated.So you should be thankful you only have a 20% success rate getting contact info, because if they gave you 100% contact info you would go bankrupt MUCH faster sending all these people mailers.Nothing can target motivated sellers, NOTHING can.

Sounds like he was feeding you a line of garbage. 

This alone really turned me off, we stay in hotels now and I have gotten similar feed back from other friends and family members.

The price you pay for being part of the Disney World spoon-feed of guests is that the barrier to entry for profitable STRs (ones that leverage close to or max LTV) is very, very high.  

He'll have them feeding his business for years.

A furnished mid-term rental or month to month lease can be well worth the small incremental monthly cost for this flexibility if you are serious about finding a great live in flip candidate on your timeline, not that of your employer's. 

See the Robert Liu feed about them!

So to answer your question, I don't think buying the cash buyer data feed is necessary.