Or you could set a cap on the amount each developer spends on their tools. Say $2499 total and let each developer decide how they use the fixed resource.
Being that you are such a strong advocate of having many options. Go back to Jeff's original e-mail - .NET versus VFP.
I simply clarified - "right out of the box".
Are you saying that VFP 9 Pro, right out of the box, is deficient in some way and requires more tools?
Kevin