In the Raleigh, NC area mid-to-3/4 high-end custom homes in the 4,000 sq ft area w/ 3-car garage run around $175 to $200 per sq ft including the lot with lots running typically from $100,000 to $150,000. That means the build portion of the cost is typically in the $140 to $175 per square foot range.
Another popular theory is that the Joker is Jason Todd a.k.a. (another) Red Hood a.k.a. (briefly) Nightwing. Jason was brutally beaten to death by the Joker in 1988's 'Death In The Family' storyline. In all honesty, this would be a little difficult to explain: Jason Todd beaten to death by the Joker who happened to be Jason Todd all along.
Jason Todd is a vigilante superhero with multiple names. Originally he was the second Robin, Batman's sidekick after Dick Grayson grew too old. During A Death in the Family he was murdered by the Joker, although he would be resurrected many years later during Under the Hood and become the anti-hero Red Hood.