Best Buy planned dramatic action Thursday after it posted a $1.7 billion loss for the last quarter of its fiscal year. As part of hoping to save $800 million by its fiscal 2015, it would close 50 of its "big-box" stores during its fiscal 2013, which started with the beginning of March. The retail chain hadn't named the stores in question, but expected these and other cost savings to cut $250 million in 2013 and $300 million just for retail by the 2015 target.