vCloud API would let you see what is. Therefore you would need to program something to track changes over time at given intervals.
Usage Meter won't track networks/firewalls/vpns, etc. It tracks License usage, not VM usage. It's also only for VMware Virtualization Service Providers (VSPP).
Chargeback will track the compute consumption (pCPU, pRAM,Storage) in a general sense. But won't track Network usage (bandwidth) in some situations. It doesn't track firewall usage & VPN usage last I checked.
