My landlord served us an N12 to move out by end of July. He…

Second opinion] Hi, my landlord served us an N12 to move out by end of July. He said he is moving back due to a divorce but if we are buying the place he will sell to us for the price as in without any conditions. We have gone back and forth and first he agreed to fix up the maintenance items but then he changed his mind. Since the rental market is high and hard to find another comparable place we are still going to buy it under the pressure. I asked him to deduct the last month rent, the 1 month rent of N12 compensation and the water heater rental $6k that I have paid over the years (should be landlords' responsibility) but he said he will not deduct it. the price is as is. So my question is after the sale can I still bring it up the tribunal and get the money back?
Landlord served us N12 since he said he is moving into the unit. If we are buying it then he will look for another place. He is doing it in a private sale and saying the price is selling as is and he would not accept counter offer.He is refusing to deduct the water heater rental cost i have paid over the years ($6k) and it was stated on the lease agreement that it is the landlord's responsibility1. He is refusing to deduct the last month rent from the sale price2. He is refusing to deduct the 1 month rent compensation according to the N123. He refused to fix up the maintenance items I sent him long time ago