Initially they were finding deals (whether they knew it or not), but lately there are more and more properties being sold at prices they really do not justify {but they look like a steal compared to TO}.  

Hey @Rob TartreRentometer can help.Also go to Craigslist and look at rentals in your property area, just make sure you're comparing Like buildings (condo vs townhome vs duplex vs SFR)

I know of one on Long Island that I use on the regular for my traditional buyer and seller listings, who is also skilled in double closings.

Do I go to a traditional bank and get it refinanced?

Make sure to provide the real estate agent - your lease agreement including all additions and provisions, instructions on how to screen the tenants (you set the terms according to the specific house in the specific neighborhood comparing to other rental in the area). and you let the RE agent list the rental in the MLS.

Also, I am confused. how is your lender providing you a number that you are comparing to be off by a mile? 

If you're analyzing for rentals, I've found rentometer.com to be a decent resource for finding comparable rents.  

If they can do it, and depending on where it is, the lender uses 75-85% of the comparable rents or leases for income to help people qualify. 

If people factored in the costs to operate a property as part of the purchase equation, then perhaps they would be able to compare apples to apples, but that's just not how we value property these days.

I’ll evaluate a property myself and compare with the BP calculators to make sure my math is correct.