Sale prices for Tulsa County are usually up-to-date, but I usually verify with the Tulsa County Assessor's website just to make sure, sometimes there are wonky numbers on Zillow. 

We just bought a Mobile Home with land for $4,000 before the guy lost it.I checked the title online for any encumbrances to verify it was clean.

If your adjustable goes to 11%, then will eat up a good portion of your rents.My 4plexs that I purchase already had tenants in place, with verifiable leases.

Verify fees because they post fees but they are just a snapshot of what you might have to deal with, could be +/-.

Also it might help that I have a verified business Paypal account.

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

@Ana MealsRecommend reading our series about “How to Screen Applicants like a Pro”:https://www.biggerpockets.com/member-blogs/3094/93296-how-to-screen-applicants-like-a-pro-part-1-verifying-credit-reports

The buyer has a responsibility to inspect and verify what they are purchasing.If the problem was "reasonably apparent" to an observer, then you may be liable for failing to investigate.

People love to throw the word mold around but there has to be a biologist test to verify.

Trust but verify.