@Wendz - You have a very good point there. There are ladies who are impossible to break up with. They'll cry, threaten, plead, call your sisters/mum, camp at your work place etc. For such ladies, one can forget the civil break up. But everything else I said holds.
About your bro, tell him to RUN! This lady will mess him up big time! It might take him ages to ever allow any other lady in his life.
Never count on making a good sale. Have the purchase price be so attractive that even a mediocre sale gives good returns.