In your chart view, you can absolutely widen that field.
1. In the Chart Module, go to the 'Show' tab.
2. If there is not a view in the 'Chart View' list, you should add one.
3. Double click on the chart view to edit the properties.
4. In the LL corner, there will be a 'Fields Showing' box. Double click the Amount
5. Change the width of that box to something larger (say 60 or 65).
6. Repeat until the chart looks the way you want it to.