ALDI, an international discount grocer, has more than 1,000 stores in the U.S. and is preparing to build its first store in New York. The grocer's debut in New York is expected to increase competition in the sector. "They shake up a market," said Burt Flickinger, a supermarket consultant. "And they don't come in with just one store. They'll open five, then 10 and 15."