The two data visualizations in the article are poorly designed.

They show line graphs where the X-axis is the type of EC2 instance and the Y-axis is the price. Firstly, the X-axis of any line graph should be time. Or perhaps some other variable that "progresses". It's bizarre to use a category to label the X-axis of a line graph. Secondly, the X-axis is not ordered alphabetically, but seemingly randomly.

I don't mean to be harsh, but a better data visualization would be a bar chart, not a line graph. Bar charts are better suited for categorical dimensions. Also, the type of EC2 instances should be grouped and/or sorted, but not randomized. This way, the information from the data visualization can be parsed more quickly and easily.