Just pay for professionals because that's how you insure stakeholder buy-in for the project. Is this something donors expect you to be spending time on? Have the executive team green lighted the action? Budgets are always a bright line test.

If not, then there is a good chance a volunteer is wasting their time...and worse, you will be wasting a volunteers time simply by not valuing it. People smell that pretty quickly.

If you want professional work, hire professionals. Good luck.