Probably a simliar reason as why I won't normally give an up-front price when doing contracting work. For better, or for worse, "enterprise" folk are trying to

Probably a simliar reason as why I won't normally give an up-front price when doing contracting work. For better, or for worse, "enterprise" folk are trying to sell "solutions" and not services. This usually works out well for them, because the people who they're selling to don't usually understand the technical minutae, and will often get the details wrong or incomplete.