I'm trying to put together a document for work that salespeople in a large company can follow when selling VoIP infrastructure to clients. I know most of the benefits, and have listed them in the document, but I'm having trouble finding recent pricings of external analog phones versus VoIP, even just between sites. I'd like to throw in hard numbers for customer confidence. Has anyone got any case studies or anything? My google fu is borked on a Monday morning.