To get access to the "MLS" In 98% of the cases you must...Hold a Real estate licenseHave a membership with the National Association of RealtorsHave a membership with a state orginizationHave a Local board membershipPay for MLS AccessIt runs in the area of $1500/year.Or you could just find a company that sells access to an advanced auditor search.

Property tax - get actual numbers from county auditor, don’t trust listing agent’s numbers.

Auditor shows them taking the home back at 30K.

I check things like taxes on the county auditor site to confirm numbers and the use my knowledge of rents in the area to check the validity of the given rental income.  

Visited the county auditors site.

All strategies require a list.You can get a list for free on the local auditor/appraiser site. 

The county auditor may have an online searchable webpage.

The local Auditor will likely change your value to what you paid and will then look at your building permit history to determine what your assessed value will be in the future.

@Eddie Pietschmann You should obtain lists from the county auditors' website.

Here are a few pointers, - Background Check, Criminal record, eviction record, credit report, bank statements, previous landlord referral (look up the property on the auditor to verify that it's not their friend). - Ask them what they can share with you.