They will have additional costs for mailing & online campaigns to get leads.

Now I found one that specializes in real estate investors that was recommended by an online mentor.

Yes, there's a lot of information online, but nothing replaces and EXPERIENCED honorable agent.A seller whose listing expired with a different agent/firm is now my client; the other agent was from a town 45 minutes away from the flip property....the listing expired. 

Consider connecting with local REI meetups, hospitality groups, or even online forums like this one to find like-minded investors.You could also pitch your successful track record to potential equity partners.

They are highly secretive however - no online presence under their names while being very tech-advanced, they also installed like seven cameras around the house perimeter.

Definitely join your local chapter of REIA (real estate investors association) or join one of the ones that are fully online (Columbus and Cincinnati).

You can find online which larger institutions are buying in a specific area and try and reach out to them.

The forms are online, and it costs $100 per filing. 

I use QuickBooks Online for all of my clients.

And you can be a landlord that gets a very poor return because they haven't utilized their space well by changing the layout.