That's always a tough question, given that applications vary widely in price based on whether it's a hosted or installed delivery model, user-based or organization-wide subscription model, or a per-gigabyte or other data model. I would use the cost-per-sale and cost-per-lead values to help determine what a system is worth to a business. For most customers, services are going to be anywhere from $20 to $350 per month per user.