I had a guy take down part of a block wall, bring in a bulldozer, bust up the sides, knock holes in the bottom, compact and level the soil for 2K. 

Then just plan on knocking them down if they are in that bad a shape.  

I havent seen too many investors knock down these properties- avg rehabs are usually anywhere from $10k - $30k(Providence) $25k - $75k(Boston), if youre dealing with a mostly cosmetic rehab.  

It has been a fairly long time coming, but I am dipping my toes in it.My wife and "drove for dollars" a couple of weekends ago, wrote down addresses and I just submitted my mailer list.I have also been walking the streets, knocking on doors and placing post its if no one answers.  

He knocked most of it back in but it all had to be touched up again after that.

Door knocking - cost of gas + ability to take a bit of abuse ! 

I would advise not to knock on doors.

Also I'm assuming not having a lot of disposable time and not being a cash buyer will knock out most non-MLS options.

I'm heading out to knock on doors today, a recommendation from the BP podcast show #86.

I am not knocking anyone here for how they feel on Detroit hell I have said the same thing.