If you are looking for a cost-effective phone system, then VoIP is the better choice as opposed to PBX. This is because there is only a minimal upfront cost that you have to pay because of its lighter infrastructure load compared to the PBX phone system. In fact, all you need to do is to invest in VoIP-enabled phones, subscribe to a reliable internet service, and then you are all set.
Also, choosing the VoIP system will allow you to save money as it has lower monthly costs. You will also get to enjoy a simplified and hassle-free billing experience because VoIP combines your bills for your telephone and internet service.