Well at this point all we know is that you're not a millionaire. Neither am I, so we have something in common other than an interest in good sound.
I'm not even sure what you mean when you say "arms". There are speaker mounts you can use, or are you talking about a ledge or shelf or something? Arms on what? The wall? The entertainment center? To the sides? Forward of the center? Speaker placement counts for a lot if you want good sound. A lot of folks tend to overlook that.