The quick answer to this question is yes and no. If you are only looking to reduce your call costs then the simple answer is no. Even if you have several locations all linked via an MPLS network for example, it would be several years of toll free calling between sites before you realised any ROI. If you are looking to work smarter by reducing travelling time for example then the answer is yes.
Let's try a different question, what is Unified Communications and will it save me money?