This is not always accurate but I use it as a great rule of thumb.

First, listing all my properties as line items with their value gives me a fairly accurate snapshot of the total of my holdings.

Also, it seems most private lenders get points is this accurate?

You will need to take that into consideration along with taking out for repairs/maintenance, cap/ex, vacancy, taxes.It's good to factor each expense individually to be as accurate as you can. 

I would also like to know of an accurate reliable skip trace site.  

Careful on Zillow - their estimates are all over the map and not accurate.

This is a heck of a gamble.

That would probably be more accurate.

For $50 a month, you are really taking a gamble on not getting the 3 showers a day tenant like @Colleen F. talks about.

It would be wise to learn an accurate vacancy rate and include it in your calculations.