Agreed, salaries are the main expense; but not writing code goes faster than writing code in a productive language!
Unless you go to a completely unchartered territory (as e.g. Viaweb did), and there's no library to get you halfway done, you should pick the best library and just accept the language it happens to be written in.
Of course, a good language supported by a great community has better chances to have the best libraries. I'd even go further, and argue that "language goodness" should be defined by its ability to let great libraries and community emerge, rather than how fun and concise it is to code in it. This property is not entirely determined by the language's syntax, semantics, or even implementation, but it is what truly matters, what gets things done or not.
Unless you go to a completely unchartered territory (as e.g. Viaweb did), and there's no library to get you halfway done, you should pick the best library and just accept the language it happens to be written in.
Of course, a good language supported by a great community has better chances to have the best libraries. I'd even go further, and argue that "language goodness" should be defined by its ability to let great libraries and community emerge, rather than how fun and concise it is to code in it. This property is not entirely determined by the language's syntax, semantics, or even implementation, but it is what truly matters, what gets things done or not.