How old is "too old" for an office phone system?

[donpabio12]

We currently are running a 7 year old phone system. It is not VOIP but stil pbx. Our company is moving in a few months so I approached the CEO about an upgrade. His response was 7 years is not too old for a phone system.

I would love your thoughts. I plan on working on a proposal to show the cost effectiveness in upgrading to a system I can manage much easier an is more expandable.

Any input would be much appreciated.