"At this price level, it's not designer kitchens and indoor pools that lure buyers. It's land — preferably oceanfront land — and preferably lots of it. The latest addition to the nine-figure listing club is on Martha's Vineyard. The property, known as Homer's Pond, is a secluded estate with 314 acres off the south shore of the island."

"Yet while the $100 million homes may grab attention, they don't always live up to their price tag. Casa Casuarina, the mansion in Miami once owned by designer Gianni Versace, was listed last year for $125 million, but the price was recently cut to $75 million. 'There's been a perception that pricing over that threshold draws eyeballs to the property and gets it sold," Miller said. "Even though the price may have little to do with its value.'"