I don't understand the question? What evidence do you need? That a colo cage can be $50k/yr? Call Equinix and ask for some dedicated space.
Who's going to go through the trouble of buying and deploying full DAR with an HSM of their own, and then put it in a common shared hosting environment instead of a dedicated, secure environment?
Can you provide some evidence around these types of costs and benefits over a reasonably secure rack in a reasonably secure data center?