Does anyone know the difference between these two. Or is the guy at HD just overworked. He said he does not know the difference. He said the 13ncmh is selling at the store for $669. Last week I was at HD and the 30 was $669 and the 13 was $535. That was also the online price. But just checked today online and the 30 is $999 and the 13 is $519.