So we fixed the grading around the back of the house and then had to dig a ditch 6 feet deep along the side of the house to channel the spring water away from the basement. 

When I dig  a little deeper into the conversation to find out what exactly happened it turns out that maybe they did not have any policies and procedures did not follow the lease agreement they let the tenants stay in the house for six months got taken advantage of and now they feel that they got screwed when the reality was they never really ran their properties like a business and they were hoping that it will work out okay because they had "a gut feeling"...

To dig a bit deeper into your 150 ARV here, assuming a 35k-40k rehab as 25k isnt enough (at an assumed $2-to-$1 ARV value add from rehab dollars), are you seeing distressed properties around 70k-80K that would work in the city? 

However, you need to dig a little bit deeper and find the value in a property that others might have overlooked.

Support the slab , then dig a footer around the outside , pour the footer , then lay some block to hold the slab .

Happy to offer a phone call if you would like to dig a bit into the market and how it might mesh with your needs/wants.

If you dig a little deeper, she writes a good article about how some college engineering students cheated on their exams. 

Costly to dig a foundation from the backside of the house. 

I would possibly cut a little slack, not a lot, but see if perhaps they are willing to dig a little deeper for you. 

DM me and I’ll send you some information and you can dig a little deeper to see if you would be interested!