Getting a some what accurate costs from the electric company to run the power can be a challenge too.

Locate and attend 3 different local REIA club meetings great place to meet people gather resources and info.

Scott The Book on Flipping Houses,The Book on Estimating ReHab Costshttp://www.biggerpockets.com/flippingbookLocate and attend 3 different local REIA club meetings great place to meet people gather resources and info.Consider checking out HUD homes for small multi's owner occupied gets first crack.You might consider Niche or Specialized Housing like student housing.

Sometimes it's choppy, occasionally so still it reflects houses accurately.

I would suggest you research realtors in the area who sold those 2 comps and obtain a market value from the realtor to get an accurate picture.

Would that  an accurate statement? 

Zillow isn't all that accurate.

Given you're aware of unrelated business income tax, then I gather you've already learned you need to use a self-directed IRA (SDIRA, which could be a Roth) to invest directly in any real estate, including crowdfunded projects.I understand the 'safe' real estate/crowdfund investments, which don't encounter taxes with the SDIRA include (a) loans, to be where you are receiving interest and return of principal only (no share of profits), and (b) 100% equity deals into longer-term buy and holds. 

I usually have a few agents I can rely on to gather comps to help find the ARV of a property but the response time is much too long for me.

And you get the benefit of having 50 past ones to catch up on.Locate and attend 3 different local REIA club meetings great place to meet people gather resources and info.