Moral question - What is the right thing to do here?

Alright – so I have a bit of a pickle that I would like everyone’s advice on.
Myself and my friend, Call him C, are renting a condo form a friend of mine. Let’s call the land lord, Friend J.
Rent is cheap, and everything is hunky dory. Upon moving in, I told Friend J and Friend C that I would probably buy the place in a year. After moving in, I decided it is a little bit on the sketchy side of town, and would prefer to just rent it, instead of own. I haven’t gotten around to tell friend J that I won’t buy it yet.

Today, our furnace breaks. 600 dollar bill. Friend C, is freaking out that friend J will kick us out. Personally, I don’t care if he does… I just want to do right by everyone. So my first inclination is to offer to pay for the entire furnace bill, then after doing so say… oh, by the way I don’t want to buy the place, but I will most likely live here for 5 or so years. Is this reasonable? Does that seem fair to everyone?
What would you do?