Top executives at Tiffany & Co., the world’s number-two luxury jeweler, must have been pinching themselves last week. Things simply could not be going any better at the Manhattan-based global chain. The good news started with a third-quarter profit report that showed Tiffany earnings up 27 percent. That kicked off a stock rally that helped triple Tiffany’s share price over its 2009 low. And then last Monday the White House announced a tax cut deal that will add an average $360,000 to the discretionary income of America’s richest 0.1 percent, the high-end luxury sector's prime clientele. Those extra dollars should mean even hotter sales for Tiffany’s swank new handbags like the lizard-skin Laurelton, a $4,800 offering lined in the retailer's “instantly recognizable robin's-egg blue.”