Is there any room for it to be in bad enough shape that it could tank those estimates due to excessive rehab/repair costs?

I just have to be a contrarian here @Caleb Heimsoth  as Caleb states I cannot think of anything risker than remote rehab for beginners.. keep in mind the author is a very experienced real estate professional and what works for him simply is not germane for beginners I know they want to sell books on this site.. but I fear there is going to be some really sad people that try to do this and simply don't know what they don't know.. all to just save 5 to 10k  extra that a flipper that does all the work and takes all the risk makes bringing you a finished product.. you can lose 10 to 20k in a heart beat doing this if not more.. 

By my calculations, you'd lose $100-$200 a month with the deal price and rents as the are.   

You will be losing money if the market is static or depreciating. 

Indy's on the verge of losing what little it had to make in not an armpit between St.

Or, you can let it ride and if you lose it all, how will you feel?

In the long run, the hauling is no fun at all, and I'm convinced we're losing money on it, but it makes sense to start replacing with used if a new tenant with a questionable past in rentals moves in and stuff starts breaking right and left.

So we started flipping a few houses and there were some wins and loses at first.

The most successful preforeclosure investors I've met largely focus on being there at the end, when the owner has exhausted all their options and is truly about to lose their home.

This way if it goes south you walk away and lose less money.