Joel Spolsky wrote an interesting essay (http://www.joelonsoftware.com/articles/CamelsandRubberDuckies.html http://www.joelonsoftware.com/articles/CamelsandRubb

Joel Spolsky wrote an interesting essay (http://www.joelonsoftware.com/articles/CamelsandRubberDuckies.html http://www.joelonsoftware.com/articles/CamelsandRubberDuckie...) that explored this issue without being able to come to a conclusion, though I do agree with him that you should err on the side of greater volume and less per-license because there's a hidden value in increased volume (word of mouth) that can't be made up with fewer, more expensive licenses.