Some developers have a love/hate relationship with JavaScript, as evidenced by a recent article which lamented about JavaScript being more annoying than Java. After reading that article, one developer pontificated about the role JavaScript has played in his career, and just how much a single line of JavaScript typically cost.
The many problems that come with trying to create an app made purely with JavaScript soon become apparent to anyone who has attempted to do so. As such, JavaScript is typically used along with other programming languages, and also typically, the JavaScript part of any project takes longer to code. That alone tends to indicate that JavaScript is line for line more expensive to produce line per line, compared to Java, C++, C# or most other languages.