Can we save money by using our own Project Managers?
Why use an external Project Manger or Program Manager?

"We already have PMs and a PMO", "Can't the a scrum master handle it all?"
We hear things like this from clients frequently, especially when trying to keep the cost of a project down. In actuality, not having a PM or trying to use a PM for a program level initiative will often cost you more money in the long run.
For many organizations, Project Managers focus on IT delivery projects. The projects may include major assignment areas like Analysis, Design, Development, Testing, Delivery. Even for Agile projects, where there may not be any PM involved at all, the Scrummaster's role is not to focus on tasks outside the Sprint but rather to ensure the Scrum team abides by the practice of Scrum. There is little thought or after thought about the impact of the change on the organization, the training, communication, support or change management activities.
The in-house team may respond with statements like "we've never done that in the past" or "This is the way we've always managed projects". These statements are precisely why organizations benefit from outside help who bring fresh perspective and the latest tools and techniques to the project.
The external Project/Program manager is highly skilled at managing cross-functional activities. Ensuring that all areas of the project are accounted for with a comprehensive plan. These resources are adept at a multitude of project management software tools such as JIRA, TFS, and Azure DevOps to name a few. The external PM/PGM can navigate an organization without political history or agenda, they have a job to do and they focus on getting it done. They are professional risk managers. From dealing with sudden team or organizational changes to company mergers, technology shifts or even Covid, the external Project/Program manager has encountered risks across organization, industry and project, they have learned first-hand the outcome of different types of mitigation and have gained the ability to foresee risks before they impact projects.
When you're getting ready to begin a large program level initiative, consider the tolerance for failure and consider the benefit of engaging an external project manager expert.