Is this method considered against the law? 

Because those methods are fundamentally flawed.

However, she was highly demanding and I didn’t appreciate her negotiation method by intimidation.

Same issue with a Registered Agent.Either method are fairly inexpensive and very easy to do yourself.  

Quote from @Brian Bowen: Is there a good free method or resource to find owner contact information?  

Playing the long game, it's not for those chasing rainbows, definently for the LT planned methodical focus. 

Some services provide numbers that have been involved in litigation, so those are the ones you should definitely remove from your lists.If your lists are hyper-focused, you might manage to get by with fewer removals from the DNC list.There are also non-DNC-related methods available, such as direct mail and digital marketing.

LeadSherpa is a good service i had a lot of experience with if you want to go that route.The two best strategies I’ve found are inbound methods: direct mail and Google Ads.Direct mail can be expensive, but it can also yield highly discounted properties.Google Ads, on the other hand, doesn’t require data extraction like calls, direct mail, or texting.

Or would you suggest other methods to gather data and insights before committing to a subscription?

As an accredited investor you have access to hundreds of new potential syndications every month (and crowdfunding deals which are the same thing except are allowed to market on the Internet).You may want to start off on a site like CrowdStreet or FinResi , where you can view the variety ( different types of asset classes, strategies, stances) and start to come up with your own method for looking at deals (which matches your unique, personal  risk tolerance, financial situation and financial goals).Thanks Ian.