@m411b - I think you will find that this model is not just limited to ESET. It is, in fact, adopted by thousands of businesses who realise that, amongst other things, server security is a different animal compared to workstation security, and that businesses can offset operating costs against end-of-year tax payments.
The result is that, generally, server (and thus business-oriented) products carry a higher price. Alas, it may not be ideal but it is what it is. Example, Symantec offer not only endpoint clients but a client for cloud, a client for enterprise, etc etc etc. Do you not suspect that the pricing model for different physical, virtual, server, workstation environments will be the same across the board?
Supreme prime example: Microsoft: is the workstation OS the same price and even pricing strategy as workstation? Why not? Because Microsoft, IBM, and others discovered early on during the rise of the personal (and cheaper) computer that they can gather more money from business products than from home products.