This could be Amazon's next big acquisition (AMZN, DG)

Amazon is planning to acquire Whole Foods for $13.7 billion, but if it really wants to shake up the grocery sector, it should consider buying discount stores, according to one analyst.
"If the goal is to fully compete against Wal-Mart (and the low-end), then could Dollar General be next on Amazon’s buying list to go after an arguably larger part of the U.S. population?" Gordon Haskett retail analyst Chuck Grom wrote in a research note Friday. 
The Whole Foods acquisition gives Am