I'd go for it. With the money you would be saving you could plunk down $600 bux for a new fridge in only 2 months time (I don't know how much a really good one costs, the fridge in my kitchen came with the house). Even if you had a $230 heating bill per month that's still a savings of $70. Not to mention in the summer months when you wouldn't need to use it at all, that's $300 in your pocket right there.

And don't underestimate the human ability to cope. In no time at all you wouldn't notice the floor slanting. And don't be too shy to haggle. Ask for the first month or two rent free and state your dissatisfaction about the mini-fridge and floor. Worse comes to worse he says no and you move in anyway. But you might be able to get that new fridge within a month's time.