Baltimore city has a convenient site to look up if a property got some code violations.https://cels.baltimorehousing.I...However, it looks like the violation notices there don't show exactly what the issue was.

Have other people noticed the market being overly hot recently? 

The price to paint, or reroof doesn't decrease that much for a sub $1000 per month rental.

Tina I saw the calculator and then noticed your from Detroit, MI.

If violates the lease, put it in writing and send him a warning notice via certified mail. 

Put it in writing and give the necessary advance notice for your state. 

Ultimately you're solving problems in real estate and if the difference of market rent to his rent is XYZ$, then decrease that from the purchase price. 

The lot/home rent ratio is decreasing and I think that trend will continue as lenders in our area become more sophisticated and force this model more.

However, if the current lease is in a month-to-month status, then you can make changes to it, but will need to give appropriate notice after closing. 

I noticed in your profile that you recently moved there, where did you live previously?