A license for all 2D charts as well as the right to remove Plotly links and references costs $249 per developer per year. For access to the 3D graphing, it's $995 per developer per year. The annual fee as opposed to a one-time purchase is important to note if you're considering a paid version, since you'd likely be in license violation if you later decide not to renew -- unless you get rid of all your graphics created with the advanced versions.
Below is a sample Plot.ly graph using mostly default options plus some additional code to make series names display correctly. The Plotly library does not appear to offer responsive design (changing graphic size as the browser window resizes) with basic graph code.
And, here is the same data graphed with the Highcharts library:
Both libraries offer the ability to click series on and off, which is useful in a case like this where one series has smaller totals than the others. Desktop and laptop viewers can also mouse over the graph to see data points. Tapping on an iPad works for both libraries, although I had trouble getting data points from Plotly's library when tapping on an Android phone. Plotly offers pan and zoom options for its graphs as well.
The Plotly library will likely appeal most to users of the Plotly site who would like the ability to generate similar visualizations on their own websites. If the Plotly look-and-feel appeals to you, you don't mind links back to their site (or you're willing to pay every year for the privilege of removing them) and the available visualization options meet your needs, this might be worth a look. If not, check out my chart of other available free tools for data visualization and analysis.