Re: Roll your own
Roll your own is how we've been doing it forever. There's nothing wrong with that. However, there is a scale at which rolling your own becomes more expensive. It's not just about the acquisition costs, but the overall life-cycle costs of delivery/management/retirement that large organizations have to consider.
If you have plenty of admin/people talent and that's not going to change, then maybe roll your own is the best way. If you're constrained on admin/people talent, you may want to consider some of these HCI solutions.
The vendor I work with want's to provide the solution that works best for me. If you're sales team doesn't recognize that, you need to ask for a new sales team.