For you military/veterans, police, fire, ems types.......buds police supply has a S&W M&P15 Sport 5.56 for $520 delivered. Good price to me. I own an M&P 15OR and love it.
http://www.budspolicesupply.com/catalog/product_info.php?products_id=7680
http://www.budspolicesupply.com/catalog/product_info.php?products_id=7680