AR prices are as low as they've ever been. You can get an entry-level carbine for $400, or something pretty darn nice for $800. So, for about the same money, you could have something accurate and reliable...and useful. I'd probably go that route, unless that MAC 10 has some kind of special collector appeal to you. They do look cool, and I don't really like to knock on any one's personal choice of firearms, but they are what they are. And they are definitely cheap stamped junkers.