Just wondering why you would pick this over say jquery-ui or a combination of free and open source solutions?
Is there any place where we can compare the various charting libraries?
Now look at the Kendo time picker. Design and usability are crucial to a successful product, so I'd say this looks like a smart investment, although I'd have to tinker with it more before buying.
http://trentrichardson.com/examples/timepicker/
It extends the standard jQuery UI datepicker but you can turn off the date picker part leaving the time picker.
I didn't like that one because dragging a slider for the time seemed like a lot of work.
I'd rather click, so I ended up with this one that is based on jquery ui as well: http://fgelinas.com/code/timepicker/
For an ISV, $399 is next to nothing.