I'd call the plumber, ask if he knows what caused the slow drain - and verify he was paid in full.My lease also says they are responsible for clogs unless the stoppage is between the outside of the unit and the street.I'm guessing that being a A Class tenant they did not want to put up with even a slow drain and have the $ to pay the bill and know it's their responsibility and that they're only looking for a little goodwill or a 'thank you' in return.

Also due your due diligence on whatever is specific to your location: radon, expanding soils, next to the goodwill (dumping)... whatever you need to watch out for in your area, do your own due diligence. 

They won't appreciate at all, tenants will not be good, will not be in good neighborhoods, and chances are that the rehab is shoddy. 

I agree regarding the buyers screening, nothing good will happen if I sell the property to just about anyone who can put up 10% of the house value. 

But, a little experimenting doesn't hurt.I actually learned about the idea of raising prices from a marketer who worked for GoodWill, of all places. 

Because you both are 50/50 and they put up money and you are performing good will by managing, you both should split the expense.

If they're good, great: you'll have some lenience and goodwill for a long-term partnership!

A little goodwill goes a long way to foster healthy business relationships.

They remained unyielding in their stance.After their decision, in goodwill, I offered to show them my roommate agreements for 12 months terms (which I did), terminated my roommate's agreement as they requested (which I did) and even proposed selling my condo (currently for sale).

He doesn't take things on good will.