It's a great source.

Also fwiw source of income is a protected class.

Cap rate, cash-on-cash, NPV, equity multiple, IRR...Can anyone recommend a good source of information on using these rates of return when underwriting deals? 

I tried to search for online sources but not so lucky to find one.

Yes, definitely ask for bank statements to confirm the rent payments from the same source each month for the amount of time they have been renting.

I've heard from some of my sources that the owner made renovations to the condo and those costs may be attached to the property.I basically DO NOT want to get burned with this purchase so I'm trying to find out as much information as I possibly can BEFORE bidding at the auction. 

DON'T GO OVER IT FOR ANY REASON.Now calculate what your max offer is based on the terms you get from the lending source you're working with. 

A lot of deals can be created off MLS listings, but I would recommend including a different source for your leads. 

Since they seem to only be a source of trouble, I'd have them vacated. 

Sounds like I just need to find some wholesale sources that are independent and not part of a large corporation.