Modifying cloud resources while being used

[minondoa]

In the case that some VMs have already been created for a resource and the user changes said resource, right now the DRM4G will just maintain those VMs with their "old" values, but will use the "new" values when creating new VMs.
In the case that for example the pricing changes, the old ones will ignore it and keep using their outdated values to calculate how much money has been spent.

¿Should this behaviour be changed, or should we just warn the users and make them create a new resource each time a resource is modified?