Goldman Sachs is upgrading SanDisk (NASDAQ:SNDK) to Buy from Neutral with a $45 price target this morning as they see an attractive entry point for the stock:1) Post NAND industry oversupply and price pressure in 1H12, the firm expects a return to supply/demand balance by 4Q12 as they believe suppliers such as Samsung and Hynix are pushing out capacity expansion and shifting some NAND fab capacity