Forget $1 billion — can the Sept. 11 memorial at Ground Zero really cost $500 million? You don’t even know the three-fifths of it:

The goal is a $500 million memorial. But some expenses are irreducible. A rough calculation suggests that it might cost $300 a square foot to build the simplest structure to fill the 70-foot-deep hole: four 250,000-square-foot floors with no memorial, no museum, no voids, no pools and no landscaping.

“It’s going to cost you about $300 million,” [design committee co-chair] Mr. [Roland W.] Betts said, “just to get up there and build your windswept plaza.”

At least a parking garage would recoup some money . . . and that would really show the evildoers!