Call a lawyer. I’m assuming there has to be legal services somewhere in ri (rwu law clinic maybe?). Read your lease. If someone is buying it for cash to likely knock it down, your living conditions are irrelevant to the deal in the end. But get actual legal help. Find out who his agent is re the sale (unless it’s a FSBO?). Chat them up. Agents want a smooth deal and even if your landlord is being a jerk, the agents going to want this to go As smoothly as possible.