title: Formating dollars with commas on Highcharts
body: <p>I'm trying to get a sum over a stacked column in a Highcharts chart to show both the $ and commas to separate thousands.</p>
  
  <p>Here is an excerpt:</p>
  
  <pre><code>yAxis: {
     stackLabels: { 
         enabled: true,
               formatter: function() {
                     return 'Total: $' + this.total;
                 },
         },
     labels: {
       format: '${value:,.0f}',
    },
    title: {
          text: 'Total $'
      },
  },
  </code></pre>
  
  <p>The labels appear right, but can't quite get the "this.total" to display with commas for the value above the stacks. Any ideas?</p>
  
  <p>Thanks in advance.</p>