Some of them may have public web sites listing their favored vendors. 

I'm working on building web applications that can provide value to real estate professionals.

@Jerry W I would be happy to show you how this works mathematically via web-meeting.

Here's what mine does down below, from their web site.

There are some events listed on Gordon Moss web site:  http://realestateandnoteinvesting.com/events/ Can anyone else chime in about good note buying conferences?  

@Doyle Wilhoite There are a ton of podcast and articles on the web, quick google search and you'll find a lot of helpful content.

In looking through Bigger Pockets & other resources on the web; it appears this estimator is attempting to take me to the cleaners, but I'd love to hear from any of you who have more experience with this sort of thing. 

My only problem is that I can’t clone him.

Please point me to a good one source book or web site that tells me most of what I need to know.

Now, in reality nobody goes to the trouble to do all that math, but it is pretty easy to eyeball it if you are go to any of the web sites that help potential renters find a place to live and do a search on the rents.