Awesome job powdahound, and I support this comment. You could show the cost units for reserved instances as a range.

For example a small reserved instance's base cost is $227.50 per year so that's a lower bound of $.0263/hour. Then adding $.03 per hour used the upper bound is $.0563/hour.

So over the course of a year you'd pay within the range $.0263/hour - $.0563/hour depending on your usage.