Foreclosure Auctions - BRRRR opportunity?

[Tripp Smith]

Hello all! I'm based in Greensboro, NC (all connections welcome). I've been bitten by the real estate bug and am ready to take action but I have some questions! 

When I first started my real estate education journey about a month ago I thought a 2-4 unit multifamily unit would be the way to start out. After analyzing multiple deals nearly every day since then, I've realized that the kind of cash on cash return I'm looking for is difficult to find right now. In a search for a new avenue, I found the BRRRR investing method which I think could work well for the area that I'm based in. This leads me to my actual question:

When bidding on foreclosures at your county auction, how do you know what kind of repairs the place needs?? Of course if you have the cash on hand then you can fix a place up but what if you were planning on $20k in repairs and it leads to being $100k in repairs? Seems like a bit of a gamble to me. Do bidders just put in lowball bids and hope for the best? 

I do see opportunity in finding a fixer upper at below market value via auction but as a first time investor I want to be sure that my money can provide a return. The numbers are important to me. Any thoughts, tips, advice etc. when it comes foreclosure auctions and finding opportunities for BRRRR investing in general? Again, any connections in the North Carolina market are more than welcome.

Thanks in advance