Do you need the features that come with the Plus kit? You state in your question that you're thinking about it, which tells me that you haven't actually performed a needs analysis and are not sure what you need. After I perform a needs analysis I know what I need, I don't have to think about it.
The features available via Essentials Plus as opposed to Essentials are:
With 2 of the 3 requiring shared storage (HA and vMotion).
So if you're not planning to implement shared storage and utilize HA or vMotion, my recommendation would be to purchase the Essentials Kit rather than the Essentials Plus Kit.