What was your biggest cost of doing business in the last 12 months?

Just curious. A contractor friend of my suggested I ask this.  At the RCS we are not in the same business as you so my answer is of little importance.  You can't say payroll because that should be directly connected to sales, (no sales, no payroll?).  Ours is travel expenses.  We need to travel whether we make sales or not.  So what costs are you seeing?