So where are you building your Server 2012R2? Is it on physical or virtual? Sorry your post is not very clear. How many physical hardware do you have? You can also consider Essentials Plus Kit Term at half the cost of Essentials Plus VMware vSphere Essentials Kits - Official VMware Store
What are you trying to achieve? Or what are your requirements that you are trying to meet? Consider all the benefits you will gain from Essentials Plus. Such as ability to live migrate Server 2012 between physical servers, Server 2012 automatically restarting in another physical server in the event the one it was on cashes, backup solution to backup your Server 2012 (what are you using to back up your server now?) and several other feature sets.
Here are some of the features that you get with Essentials Plus
- vSphere Hypervisor (ESXi)
- vCenter Server Essentials
- vSphere Data Protection
- vSphere High Availability (HA)
- vSphere vMotion
- Cross Switch vMotion
- vSphere vShield Endpoint
- vSphere Replication
