Whats wrong with the free ESXi ?
How does effect new vSphere licensing your server? Again... new licensing comes into the game with 32 core per CPU which means 64 phys. cores in a 2s server.
vSphere essentials starts at 470 + 62,- EUR and i have to say sorry when a company cannot effort it you may think about your business. This is totally different for a private person of course! Are you a private? Whats about VMUG Adv. or Free ESXi?