Your landlord probably doesn't know what he's doing. Either he seriously underpriced the place when he first rented it to you, or he's trying to charge you above market rate. A 50% increase is ridiculous.

Probably what happened is, he's figuring on an X% income from his property. The property value went up, like everything has everywhere, so he thinks he should get a higher rent payment. This is not how it's supposed to work. Supply and demand works in the rental market. He's not guaranteed to get any return. In fact, property prices are so much higher than rents in some areas that the market value of rent won't cover mortgage, tax, and maintenance. Because of this, you're actually in a great bargaining position.

Seriously, though, I would want to move, because it sounds like he has no idea what he's doing. It's only like one weekend of work, and you'll save yourself a lot of money and grief.