Should College Football use QB helmets like in the NFL to call in plays? I've seen no down side to their use in the NFL, so is there a good reason not to use them in college?

I don't see why not.

I know some teams have the entire offense look to the sideline to get the call and the QB doesn't call the play in the huddle. But NFL teams seem to do just fine in 2 minute drill, so I don't think it would slow any teams down.

I, too, see no downside to the switch.

wonder how much those systems cost? sure can't be the reason.

Not only does it cost.....it also has to shut off with 15 seconds left on play clock. That is something colleges cannot easily do without intervention.