per VM pricing
Terremark has had per-VM pricing for a while in their vCloud express package (note not the same as enterprise cloud but uses similar technology). But you may be able to get a ballpark guesstimate as to what enterprise may offer.
Last time I talked with Terremark was almost 3 years ago I think and their enterprise cloud pricing was fairly high, like all cloud companies(I've yet to see a proposal from a cloud company that has an ROI of higher than 12 months vs doing things in house).
They are higher than Amazon to be sure - but also use much higher quality equipment and can do things enterprises expect like live migration of VMs between hosts to do maintenance. Enterprises (rightfully so) are not used to throw away VMs that Amazon forces upon you. vCloud express also allows you to (shock!) boot a VM with an ISO. Terremark is also more flexible in that they allow hybrid setups as well, physical+virtual.